tag:theconversation.com,2011:/us/topics/carbon-sequestration-5324/articlesCarbon sequestration – The Conversation2024-02-20T13:20:50Ztag:theconversation.com,2011:article/2174302024-02-20T13:20:50Z2024-02-20T13:20:50ZCarbon offsets bring new investment to Appalachia’s coal fields, but most Appalachians aren’t benefiting<figure><img src="https://images.theconversation.com/files/571772/original/file-20240128-15-bsgb8q.jpg?ixlib=rb-1.1.0&rect=4%2C0%2C1305%2C840&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">For decades, railroad tracks carried coal from eastern Tennessee to power plants in the eastern U.S.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/appvoices/6853913378/in/album-72157629262715216/">Appalachian Voices</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Central Appalachia is home to the <a href="https://ww3.arb.ca.gov/cc/capandtrade/offsets/overview.pdf">third-largest concentration of forest carbon offsets</a> traded on the California carbon market. But while these projects bring new investments to Appalachia, most people in <a href="https://doi-org.utk.idm.oclc.org/10.1080/03066150.2022.2078710">Appalachia are not benefiting</a>.</p>
<p>The effect of this new economic activity is evident in the <a href="https://storymaps.com/stories/2f4984877e0d42cdbc424d107eefc3ba">Clearfork Valley</a>, a forested region of steep hills and meandering creeks on the Kentucky-Tennessee border. </p>
<p>Rural communities here once relied on coal mining jobs. As the <a href="https://doi.org/10.1016/j.exis.2021.100990">mines shut down</a>, with the last closing <a href="https://opensourcecoal.org/df_coal_production.php">in 2022</a>, the valley was left with thousands of acres of forests and strip-mined land but fewer ways to make a good living.</p>
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<p>Today, corporate landowners and investment funds have placed most of that forest land into carbon offset projects – valuing the trees for their ability to absorb carbon dioxide emissions to help protect the climate. </p>
<p>These <a href="https://www.wsj.com/articles/wall-street-firm-makes-a-1-8-billion-bet-on-forest-carbon-offset-11667390624">carbon offset projects can be lucrative</a> for the landowner, with proceeds that can run into the millions of dollars. Companies subject to California’s carbon emissions rules are willing to pay projects like these to essentially <a href="https://ww2.arb.ca.gov/our-work/programs/compliance-offset-program">cancel out, or offset</a>, the companies’ carbon emissions. However, my research shows that <a href="https://doi.org/10.1080/03066150.2022.2078710">few local residents</a> are benefiting. </p>
<p>The projects are part of <a href="https://www.ucsusa.org/sites/default/files/2021-04/losing-ground-final-4-15-21.pdf">a wider</a> and <a href="https://doi.org/10.1111/ruso.12210">growing trend</a> of investor-owners of rural land making money but providing <a href="https://doi.org/10.1080/24694452.2017.1328305">little local employment, local investment or community involvement</a> in return.</p>
<h2>Few local jobs, little economic benefit</h2>
<p>The rise of carbon forest offset projects in Appalachia has coincided with the historic decline of the coal economy. </p>
<p>Central Appalachia lost 70% of its coal jobs from 2011 to 2023 as its <a href="https://opensourcecoal.org/df_coal_production.php">coal production fell by 75%</a> in that same period. As corporate landowners looked for new revenue streams, they found a burgeoning forest carbon offset market after California instituted a <a href="https://ww2.arb.ca.gov/our-work/programs/cap-and-trade-program/about">forest carbon offset protocol</a> in 2011.</p>
<p>Much of the Clearfork Valley was originally owned by the American Association, a British coal corporation that <a href="https://www.press.uillinois.edu/books/?id=p009853">accumulated the land in the 1880s</a>. That property passed between other coal companies before NatureVest, a <a href="https://www.nature.org/en-us/about-us/who-we-are/how-we-work/finance-investing/naturevest/">climate change-driven investment firm</a> owned by The Nature Conservancy, created an investment fund to purchase the land in 2019. </p>
<p>The previous owner, a forestland investment company, had established carbon offsets on that land in 2015, making <a href="https://ww3.arb.ca.gov/cc/capandtrade/protocols/usforest/forestprotocol2015.pdf">a 125-year commitment</a> to retain or grow the forest carbon stock. When NatureVest purchased the land in 2019, it generated <a href="https://www.environmental-finance.com/content/awards/sustainable-investment-awards-2020/winners/impact-fund-of-the-year-the-nature-conservancys-sustainable-forestry-fund.html">at least US$20 million in proceeds</a> from the sale of additional offsets. The details of <a href="https://ww2.arb.ca.gov/our-work/programs/cap-and-trade-program/program-data/summary-market-transfers-report">such transactions are typically private</a>, but offset sales can be structured in a number of ways. They might be one-time payments for existing credits, for example, or futures contracts for the potential of additional credits.</p>
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<img alt="A map shows large areas of forest in several states that are on the carbon market." src="https://images.theconversation.com/files/571770/original/file-20240128-25-lydydm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/571770/original/file-20240128-25-lydydm.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=377&fit=crop&dpr=1 600w, https://images.theconversation.com/files/571770/original/file-20240128-25-lydydm.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=377&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/571770/original/file-20240128-25-lydydm.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=377&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/571770/original/file-20240128-25-lydydm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=474&fit=crop&dpr=1 754w, https://images.theconversation.com/files/571770/original/file-20240128-25-lydydm.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=474&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/571770/original/file-20240128-25-lydydm.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=474&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Forest carbon offset projects in Central Appalachia that are on the California carbon market. The Clearfork Valley is on the Kentucky-Tennessee border in the lower left.</span>
<span class="attribution"><a class="source" href="https://webmaps.arb.ca.gov/ARBOCIssuanceMap/">California Air Resources Board, ESRI</a></span>
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<p>The investment fund is attempting to demonstrate that <a href="https://www.nature.org/en-us/about-us/where-we-work/united-states/kentucky/stories-in-kentucky/cumberland-forest">managing land to help protect the climate</a> can also generate revenue for investors. </p>
<p>In Appalachia, offset projects largely involve “improved forestry management.” These offsets <a href="https://doi.org/10.1111/gcb.16380">pay landowners to sequester</a> carbon in trees – additional to what they would have pulled in without the offset payment – while still allowing them to produce timber for sale. In practice, this often means letting trees stand for <a href="https://www.nature.org/content/dam/tnc/nature/en/documents/VA-Carbon-Sequestration-Infographic.pdf%22%22">longer rotations before cutting for timber</a>.</p>
<p><a href="https://www.nature.com/articles/s43247-023-00984-2">Recent research</a>, however, indicates that the carbon storage of improved forestry management projects may be getting <a href="https://doi.org/10.1111/gcb.15943">overcounted on the California market</a>, the largest compliance offset market in the Americas. <a href="https://www.wri.org/insights/insider-4-reasons-why-jurisdictional-approach-redd-crediting-superior-project-based">Other approaches to carbon offsets</a> could produce better outcomes for people and the climate.</p>
<p>And while the landowners and investors profit, my research, including dozens of interviews with residents, has also found that former mining <a href="https://doi.org/10.1080/03066150.2022.2078710">communities in this valley have seen little return</a>. </p>
<p>The Nature Conservancy has offered <a href="https://www.nature.org/en-us/about-us/where-we-work/priority-landscapes/appalachians/stories/cumberland-forest-community-fund/">support to local communities</a>. But while the organization operates <a href="https://www.nature.org/en-us/about-us/where-we-work/priority-landscapes/appalachians/stories/cumberland-forest-community-fund/">a small grant program</a> from coal mining and gas drilling royalties it receives from the land, the investment in the local economy has been relatively small – <a href="https://www.nature.org/en-us/about-us/where-we-work/priority-landscapes/appalachians/stories/cumberland-forest-community-fund/">roughly $377,000</a> in the three states since 2019. Furthermore, while <a href="https://mtassociation.org/energy/middlesboro-community-center-adds-solar/">some communities have benefited</a>, these investments <a href="https://www.nature.org/en-us/about-us/where-we-work/priority-landscapes/appalachians/stories/cumberland-forest-community-fund/">have largely bypassed</a> struggling former coal communities in the Clearfork Valley in Tennessee. </p>
<p>Looking for other revenue sources on these lands, by 2022, The Nature Conservancy had also leased access to nearly <a href="https://www.nature.org/content/dam/tnc/nature/en/documents/Cumberland_Forest_2022_Impact_Report.pdf">150,000 acres of its Cumberland Forest Project</a>, including parts of the Clearfork Valley, to state agencies and outdoor recreation groups. As a result, permits and fees are often now required to enter much of the forestland.</p>
<p>As one interviewee told my co-author for our forthcoming book, “For three generations my family has been able to walk and use that land, but now I could be arrested for entering it without a permit.” </p>
<h2>The rise of TIMOs and climate ‘rentierism’</h2>
<p>While a century ago many of the landowners in Appalachia were coal companies and timber companies, today <a href="https://wvpolicy.org/who-owns-west-virginia-in-the-21st-century-2/">they are predominantly</a> <a href="https://doi-org.utk.idm.oclc.org/10.1177/0896920510378764">financialized timber investment management organizations, or TIMOs</a>. TIMOs are financial institutions that manage timberlands to generate returns for institutions, such as endowments and pension funds, and private investors. While NatureVest is more diversified than a TIMO, its timberland investments operate in a similar fashion.</p>
<p>The financial ownership of timberlands is part of the much wider trend of <a href="https://doi.org/10.1093/SER/mwi008">financialization of the United States economy</a>. Wall Street-based investors have become major owners of all sectors of the U.S. economy since the 1970s, from <a href="https://www.cornellpress.cornell.edu/book/9781501750083/fields-of-gold/">agriculture</a> and <a href="https://www.scielo.br/j/gp/a/JdQdqWNHdn67pNLCJvkmnFr/?lang=en">manufacturing</a> to <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/ruso.12210">natural resources</a>.</p>
<p>Financial profits, however, often do not entail job creation or investments in infrastructure in the surrounding communities. Yet the investor-owned timberlands in Central Appalachia do generate <a href="https://www.wsj.com/articles/wall-street-firm-makes-a-1-8-billion-bet-on-forest-carbon-offset-11667390624">millions of dollars in revenue for their investors</a>.</p>
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<img alt="The hills above a home have been strip mined, where forests once stood." src="https://images.theconversation.com/files/571771/original/file-20240128-29-8ffil5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/571771/original/file-20240128-29-8ffil5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/571771/original/file-20240128-29-8ffil5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/571771/original/file-20240128-29-8ffil5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/571771/original/file-20240128-29-8ffil5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/571771/original/file-20240128-29-8ffil5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/571771/original/file-20240128-29-8ffil5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Homes below a coal strip mine in Campbell County, Tennessee, home to part of the Clearfork Valley.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/appvoices/7000037829/in/album-72157629262715216/">Appalachian Voices via Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>Political economists have diagnosed the trend of falling employment that accompanies increasing economic activity as partially the <a href="https://doi.org/10.1086/705396">result of growing rentierism</a>.</p>
<p>Rentierism is a term for <a href="https://doi-org.utk.idm.oclc.org/10.1177/0308518X19873007">generating income predominantly from rents</a> as opposed to income from production that employs people. Rural communities have acutely felt the effects of <a href="https://www.versobooks.com/products/871-rentier-capitalism">increasing rentierism in various sectors since the 1970s</a>.</p>
<p>Researchers have noted <a href="https://doi.org/10.1177/0896920510378764">growing trends of rentierism in forestland management</a>. Many TIMOs seek new revenue streams from timberlands outside of wood products and timbering, <a href="https://doi.org/10.1080/24694452.2017.1328305">such as in conservation easements</a>. As firms such as <a href="https://c3newsmag.com/private-capital-is-funding-conservation-across-the-country/">NatureVest seek to generate income from controlling carbon stocks or conservation resources</a>, there is now a growing climate rentierism.</p>
<h2>Rural resentment and a crisis of democracy</h2>
<p>A robust body of research in <a href="https://press.princeton.edu/books/paperback/9780691191669/the-left-behind">sociology</a> and <a href="https://books.google.com/books?hl=en&lr=&id=759xDwAAQBAJ&oi=fnd&pg=PT8&ots=yOy_PiDU9P&sig=u67Pv8JrCjPN2c3DaHORhJgVXi4#v=onepage&q&f=false">political science</a> shows how the <a href="https://doi.org/10.1016/j.jrurstud.2019.10.045">hollowing out of rural North American economies</a> has fed into a kind of <a href="https://press.uchicago.edu/ucp/books/book/chicago/P/bo22879533.html">rural resentment</a>. Trust in government and democracy is particularly low in rural North America, and not only because of economic woes. As <a href="https://yalebooks.yale.edu/book/9780300215359/for-profit-democracy/">sociologist Loka Ashwood documents</a>, it is also because many rural residents believe that the government helps corporations profit at the expense of people.</p>
<p>Carbon offsets in Appalachia, unfortunately, fit within these troubling trends. Government regulation in California generates sizable revenue for corporate landowners, while the rural communities see themselves locked out of the economy.</p><img src="https://counter.theconversation.com/content/217430/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gabe Schwartzman received funding from the National Science Foundation. He is a board member of the Southern Connected Communities Project (SCCP), a non-profit based in East Tennessee, and former board member of Statewide Organizing for Community eMpowerment (SOCM). </span></em></p>Large parts of Appalachia’s forests, once owned by coal companies, now make money for investors by storing carbon. But the results bring few jobs or sizable investments for residents.Gabe Schwartzman, Assistant Professor of Geography and Sustainability, University of TennesseeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2177722023-12-18T19:09:19Z2023-12-18T19:09:19ZPlanting pine or native forest for carbon capture isn’t the only choice – NZ can have the best of both<p>New Zealand’s <a href="https://environment.govt.nz/publications/new-zealands-greenhouse-gas-inventory-1990-2020-snapshot/#how-new-zealand-compares-to-other-countries">per-capita</a> contribution to carbon emissions is very high by international comparison. But so too is its potential to mitigate climate change by planting forests to quickly sequester large amounts of carbon.</p>
<p>There is sometimes passionate debate about how best to do this. Should we continue establishing radiata pine plantations, or focus instead on planting New Zealand native trees?</p>
<p>Arguments for and against each option exist – but there is also a third way that could achieve the best of both worlds: planting radiata pine forests that are not harvested, but instead transitioned over time into native forests through targeted management.</p>
<p>We need to cut emissions drastically. But we also need to remove as much CO₂ from the atmosphere as possible, especially over the next 20 years. A transitional forest model is a powerful way to help achieve this.</p>
<h2>Farming carbon using trees</h2>
<p>As trees grow they absorb CO₂ from the atmosphere and lock the carbon into wood, leaves, roots and soil. </p>
<p>The New Zealand Emissions Trading Scheme (<a href="https://environment.govt.nz/what-government-is-doing/areas-of-work/climate-change/ets/about-nz-ets/">ETS</a>) provides income from growing trees to store carbon. It is a key tool for meeting domestic and international climate change targets, including the 2050 target set by the Climate Change Response Act 2002.</p>
<p>A newly planted native forest will absorb approximately 40 tonnes of atmospheric CO₂ per hectare over ten years. By contrast, an exotic radiata pine forest will achieve <a href="https://www.legislation.govt.nz/regulation/public/2022/0266/latest/LMS709973.html">five to ten times this amount</a> over the same period. </p>
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Read more:
<a href="https://theconversation.com/meeting-the-long-term-climate-threat-takes-more-than-private-investment-10-ways-nz-can-be-smart-and-strategic-211100">Meeting the long-term climate threat takes more than private investment – 10 ways NZ can be smart and strategic</a>
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<p>In other words, to absorb a given quantity of carbon during the early stages of reforestation, it will take five to ten times more farmland using natives. Because of this enormous advantage of exotics over natives, there is a place for exotic carbon farming. </p>
<p>Some object to pine planting on purely aesthetic grounds – they just don’t like the look of radiata forests. And we agree there are some places where pine is just not appropriate for the landscape. But the urgency to mitigate climate change means we need to turn as much unprofitable pasture into forest as possible.</p>
<p>Radiata forests are also criticised for being monocultures that lack biodiversity. But the pasture they replace is also a monoculture that contains even less biodiversity. Planting trees on pasture also reduces gross emissions by reducing animal stock and therefore methane emissions.</p>
<h2>We can’t plant too many trees</h2>
<p>A year of emissions in Aotearoa New Zealand equals 78.8 million tonnes CO₂ equivalent, based on 2020 figures. To offset this for a ten-year period would require planting roughly 20 million hectares of pasture in native trees, then waiting ten years for them to grow. </p>
<p>The total area of Aotearoa is 26.9 million hectares, with 3 million of those being mountains. Therefore, another treeless country of a similar size would be required to fully offset its emissions using native trees alone. Using radiata pine would require 2 to 4 million hectares. </p>
<p>At an individual level, just one return trip from Auckland to London for one person will produce approximately 11 tonnes of CO₂ emissions. To offset this would require planting over a quarter of a hectare (almost an acre) of native trees, and waiting ten years for them to grow. </p>
<p>On current projections, Aotearoa will need to purchase 100 million tonnes of offshore carbon credits to meet its international commitments. According to <a href="https://www.rnz.co.nz/news/political/498515/the-multibillion-dollar-climate-hole-faced-by-both-labour-and-national#:%7E:text=Treasury%20had%20previously%20put%20the,around%20%24500%20million%20a%20year">Treasury calculations</a>, this will cost between NZ$3.3 billion to $23 billion between now and 2030.</p>
<p>Obviously, the country cannot offset all its emissions by planting trees, native or exotic. Reducing emissions in the first place is the priority. But from a climate perspective, we cannot plant too many trees of any kind. </p>
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Read more:
<a href="https://theconversation.com/were-burning-too-much-fossil-fuel-to-fix-by-planting-trees-making-net-zero-emissions-impossible-with-offsets-217437">We're burning too much fossil fuel to fix by planting trees – making 'net zero' emissions impossible with offsets</a>
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<h2>Restoring biodiversity over time</h2>
<p>One of the criticisms levelled at exotic carbon forests is that the carbon storage is not permanent because of the shorter lifespan of pine. But pine plantations in New Zealand can <a href="https://academic.oup.com/forestry/article/85/1/79/644814?login=true">keep accumulating carbon</a> for at least a century if they’re not harvested.</p>
<p>Also, the carbon storage is permanent if exotic forests are transitioned into self-sustaining native forests. This process occurs naturally, but can and should be accelerated by targeted management. </p>
<p>Because radiata pine needs a lot of light to grow, its own seedlings will not establish beneath its canopy. Therefore, pine will naturally decline over time and
gradually be replaced by native forest, a process that occurs naturally but takes many decades. </p>
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Read more:
<a href="https://theconversation.com/cyclone-gabrielle-triggered-more-destructive-forestry-slash-nz-must-change-how-it-grows-trees-on-fragile-land-200059">Cyclone Gabrielle triggered more destructive forestry 'slash' – NZ must change how it grows trees on fragile land</a>
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<p>To provide crucial structural and species diversity, and to expedite the transition process, native trees requiring plenty of light need to be planted, and pine trees need to be thinned. This is nothing like commercial harvesting, so the problems associated with forestry “<a href="https://www.beehive.govt.nz/release/updated-forestry-regulations-increase-council-controls-and-require-large-slash-removal">slash</a>” do not arise.</p>
<p>Fruiting natives will attract birds and enhance seed dispersal. At the same time, the income from carbon credits through the ETS can be used for further plantings, and also to fund intensive animal pest control – a critical step towards rebuilding native forests.</p>
<p>Eventually, this strategy will provide both permanent carbon storage and carbon capture that continue way beyond a century. But within decades we would also see the return of large areas of highly biodiverse native forests.</p><img src="https://counter.theconversation.com/content/217772/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sebastian Leuzinger is a professor of ecology at Auckland University of Technology and occasionally consults for New Zealand Carbon Farming. He has received funding from the Royal Society in the past.</span></em></p><p class="fine-print"><em><span>Len Gillman is co-chair of the Waitakere Ranges Pest free Alliance. He has acted as an independent consultant for local government and carbon farmers on climate change mitigation, climate effects mitigation and native forest restoration ecology.</span></em></p>Pine grows faster and sequesters more carbon. But native forest is better for biodiversity in the long run. Transitioning between the two offers a win-win solution.Sebastian Leuzinger, Professor of Environmental Science, Auckland University of TechnologyLen Gillman, Professor of Biogeography, Auckland University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2175532023-12-07T19:19:14Z2023-12-07T19:19:14ZHarnessing the oceans to ‘bury’ carbon has huge potential – and risk – so NZ needs to move with caution<p>Climate change might not be high on its immediate agenda, but New Zealand’s new government does have one potentially significant and innovative policy.</p>
<p>Recognising the marine environment’s ability to remove atmospheric carbon dioxide (CO₂), it has <a href="https://assets.nationbuilder.com/nzfirst/pages/4462/attachments/original/1700784896/National___NZF_Coalition_Agreement_signed_-_24_Nov_2023.pdf?1700784896">pledged to consider</a> bringing wetlands into the emissions trading scheme, and to <a href="https://www.stuff.co.nz/environment/climate-news/133356580/the-unexpected-climate-plans-of-the-new-government">investigate the potential</a> of kelp farms to sequester CO₂.</p>
<p>New Zealand’s <a href="https://www.parliament.nz/mi/pb/library-research-papers/research-papers/library-research-brief-new-zealand-s-response-to-addressing-climate-change/">current sequestration plans</a> rely heavily on planting forests and buying international carbon credits to offset emissions. </p>
<p>Emissions reduction and the removal of atmospheric CO₂ are both needed to keep global temperature increase to <a href="https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Headline-statements.pdf">less than 1.5°C</a>. But the country is still <a href="https://climateactiontracker.org/countries/new-zealand/">far from on track</a> to meet its obligations under the Paris Agreement, and the national goal of net zero by 2050.</p>
<p>At the same time, New Zealand has the world’s sixth largest exclusive economic zone, with unique oceanographic features for CO₂ removal that are attracting international interest. The ocean is Earth’s largest carbon sink, having removed around <a href="https://www.csiro.au/en/news/all/articles/2023/june/oceans-absorb-emissions">30% of global CO₂ emissions</a> to date. </p>
<p>New Zealand also has the scientific expertise to research the potential for harnessing its seas to help achieve national net zero ambitions. But it lacks a clear strategy for assessing risk and developing the most beneficial solutions.</p>
<h2>Benefits and risks of marine CO₂ removal</h2>
<p>Around the world, projects are under way to restore coastal wetlands by “re-wetting” drained land and planting mangroves, seagrass and other coastal plants. These “blue carbon” projects aim to restore the carbon burial properties of wetlands, with related benefits for biodiversity and coastal resilience. </p>
<p>A growing number of countries are including coastal wetlands in their climate accounting and reporting. Increasingly, these projects are tied to carbon credit schemes – which seems to be what New Zealand’s new government is also signalling.</p>
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<strong>
Read more:
<a href="https://theconversation.com/blue-carbon-could-a-solution-to-the-climate-challenge-be-buried-in-the-depths-of-fiords-205639">Blue carbon: could a solution to the climate challenge be buried in the depths of fiords?</a>
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<p>But the ways in which the nation’s marine environment could help lower atmospheric CO₂ extend far beyond coastal wetlands. There is great interest in enhancing natural oceanic processes, known as “marine carbon dioxide removal”, or mCDR. </p>
<p>In the open ocean, mCDR <a href="http://www.gesamp.org/publications/high-level-review-of-a-wide-range-of-proposed-marine-geoengineering-techniques">aims to increase</a> CO₂ uptake via giant seaweed farms, enhancing seawater alkalinity, and fertilising areas of the ocean to promote algal blooms. </p>
<p>The appeal of mCDR lies in the ocean’s potential capacity to draw down enormous amounts of carbon. But while the potential gains are large, there are gaps in our knowledge. More investment is needed to determine the net carbon benefits – and potential ecological risks – of intervening in nature in these ways.</p>
<h2>Carbon burial at sea</h2>
<p>Plants in the sea – mangroves, seaweed, and microscopic phytoplankton – capture CO₂ through photosynthesis, just like their counterparts on land. But permanently removing that carbon from the atmosphere means burying it in the deep sea or the seafloor. </p>
<p>This presents challenges. It is relatively easy to measure the carbon uptake by a <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/jpy.13249#:%7E:text=We%20propose%20a%20Forensic%20Carbon,of%20carbon%20sequestration%20to%20seaweeds">seaweed farm</a>, for example, but much harder to track the path of that carbon into a permanent reservoir. </p>
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Read more:
<a href="https://theconversation.com/new-zealands-maritime-territory-is-15-times-its-landmass-heres-why-we-need-a-ministry-for-the-ocean-210123">New Zealand's maritime territory is 15 times its landmass – here's why we need a ministry for the ocean</a>
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<p>Similarly, we need more accurate accounting for increased CO₂ uptake from ocean fertilisation or alkalinity enhancement, and the ultimate fate of that carbon in the vast and remote ocean environment. This will be crucial for ensuring the integrity and credibility of such approaches.</p>
<p>A recent <a href="https://pce.parliament.nz/our-work/news/carbon-stored-in-marine-sediments-needs-protection/">seafloor carbon map</a> has highlighted the parts of New Zealand’s marine environment, such as the deep ocean and <a href="https://theconversation.com/blue-carbon-could-a-solution-to-the-climate-challenge-be-buried-in-the-depths-of-fiords-205639">fiords</a>, that are important carbon reservoirs. </p>
<p>But we also need to consider the vulnerability of these reservoirs. If disturbed, they may store less carbon, or even release it.</p>
<h2>Lessons and opportunities</h2>
<p>There are already <a href="https://www.nature.org/en-us/about-us/where-we-work/asia-pacific/new-zealand/stories-in-new-zealand/blue-carbon/">well-established projects</a> focused on the <a href="https://www.tandfonline.com/doi/full/10.1080/00288330.2023.2245770?src=">blue carbon potential</a> of coastal wetlands in New Zealand. But overall the country lacks a clear plan for marine carbon removal, or indeed for its <a href="https://theconversation.com/new-zealands-maritime-territory-is-15-times-its-landmass-heres-why-we-need-a-ministry-for-the-ocean-210123">oceans in general</a>. </p>
<p>A comprehensive approach to evaluating marine CO₂ removal has to be informed by scientific research. And while major funding of research and development is <a href="https://www.energy.gov/articles/doe-announces-36-million-advance-marine-carbon-dioxide-removal-techniques-and-slash">happening elsewhere</a>, New Zealand’s limited resources mean it must be strategic about where it invests.</p>
<p>The many blue carbon and mCDR <a href="https://ocean-climate.org/en/ipcc-report-the-ocean-is-also-part-of-the-solution-to-climate-change-mitigation/">solutions being considered</a> internationally are a good place to start. Applying this knowledge to New Zealand’s unique environmental and cultural settings will involve <a href="https://oceanvisions.org/highlevelroadmap/">weighing up each solution</a> before committing to a strategy.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/nzs-vital-kelp-forests-are-in-peril-from-ocean-warming-threatening-the-important-species-that-rely-on-them-212956">NZ’s vital kelp forests are in peril from ocean warming – threatening the important species that rely on them</a>
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<p>Importantly, international climate policy and governance needs to be developed in parallel with scientific advances. Right now, coastal wetlands are the only marine environment included in the International Panel for Climate Change <a href="https://www.ipcc-nggip.iges.or.jp/public/wetlands/">guidelines</a> for greenhouse gas inventories. More work will be needed to apply those guidelines to New Zealand’s coastal wetlands.</p>
<p>There are good working models already in the blue carbon forums established in <a href="https://www.bluecarbon.scot">Scotland</a> and the <a href="https://www.ukbluecarbonforum.com">United Kingdom</a>. These <a href="https://www.cefas.co.uk/impact/programmes/uk-blue-carbon-evidence-partnership/">distil scientific information</a>, develop strategies and plans, and act as conduits between scientists, policy makers and politicians. </p>
<p>A similar approach in New Zealand would help advance a nationally coordinated framework of research, policy and environmental management that strategically considers all blue carbon and mCDR options. </p>
<p>Such a strategy will consider the net carbon benefit versus the risks and possible ecological side effects, particularly for mCDR. </p>
<p>But the country is well positioned to explore how the ocean might contribute to its climate goals. The scientists are ready, the government has pledged action – it’s time to get moving.</p><img src="https://counter.theconversation.com/content/217553/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rebecca J McLeod receives funding from the MBIE Endeavour Fund. She is the Chair of the Fiordland Marine Guardians. </span></em></p><p class="fine-print"><em><span>Cliff Law receives funding from the NZ Ministry of Business, Innovation and Employment for determining the role of the ocean in the climate system. </span></em></p>New Zealand’s new government has vowed to explore ‘blue carbon’ options for removing atmospheric CO₂ to meet net zero goals. But first we need a national strategy for this developing field of science.Rebecca J McLeod, Senior Research Fellow in Marine Ecology, University of OtagoCliff Law, Principal Scientist, National Institute for Water and Atmospheric Research (NIWA), University of OtagoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2113142023-11-03T12:44:47Z2023-11-03T12:44:47ZThe world’s boreal forests may be shrinking as climate change pushes them northward<figure><img src="https://images.theconversation.com/files/556952/original/file-20231031-29-4j1sin.JPG?ixlib=rb-1.1.0&rect=11%2C0%2C3854%2C2585&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A brown bear in a Siberian boreal forest.</span> <span class="attribution"><span class="source">Logan Berner</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Earth’s <a href="https://www.britannica.com/science/taiga">boreal forests</a> circle our planet’s far northern reaches, just south of the Arctic’s treeless tundra. If the planet wears an Arctic ice cap, then the boreal forests are a loose-knit headband wrapped around its ears, covering large portions of Alaska, Canada, Scandinavia and Siberia. </p>
<p>The boreal region’s soils have long buffered the planet against warming by storing huge quantities of carbon and keeping it out of the atmosphere. Its remoteness has historically protected its forests and wetlands <a href="https://doi.org/10.1016/j.tree.2009.03.019">from extensive human impact</a>. </p>
<p>These two traits rank boreal forests <a href="https://unece.org/sites/default/files/2021-07/Why%20Boreal%20Forests%20Matter.pdf">among the most important ecosystems</a> on Earth. In addition, numerous species of <a href="https://doi.org/10.1007/978-3-319-71065-5_17-1">mammals, fish, plants, insects and birds</a> make these forests home.</p>
<p>For <a href="https://doi.org/10.1111/1365-2745.13109">over two centuries</a>, scientists have recognized that climate plays a key role in determining the geographic zones of plant communities. Because boreal forests and soils face subzero winters and short summers, these forests and the animals that live in them <a href="https://link.springer.com/chapter/10.1007/978-3-031-15988-6_30">are shifting northward as temperatures rise</a>.</p>
<p>However, boreal forests’ northward advance has been spotty and slower than expected. Meanwhile, their southern retreat has been faster than scientists predicted. As scholars who study <a href="https://scholar.google.com/citations?user=BQmOlMsAAAAJ&hl=en">northern</a> <a href="https://scholar.google.com/citations?user=RBKFcQQAAAAJ&hl=en">ecosystems</a>, <a href="https://scholar.google.com/citations?user=SX1wuUIAAAAJ&hl=en">forests</a> and <a href="https://scholar.google.com/citations?user=0kHNcjQAAAAJ&hl=en">wetlands</a>, we see concerning evidence that as the world warms, its largest forest wilderness appears to be shrinking.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/OUmHWrF8MnY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The boreal forest biome, often known by its original Russian name, the taiga, stretches from coast to coast in Earth’s far north.</span></figcaption>
</figure>
<h2>The largest wilderness on Earth</h2>
<p>Boreal forests contain billions of trees. Most are needleleaf, <a href="https://www.rbg.ca/evergreens-vs-conifers/">cone-bearing conifers</a>, but there also are patches of broadleaf species, including <a href="http://www.ramp-alberta.org/river/boreal/alberta/trees.aspx">birch, aspen and poplar</a>. They support millions of migratory birds and iconic mammals like brown bears, moose and lynx.</p>
<p>These trees and the soils around their roots help regulate Earth’s climate, in part by pulling carbon dioxide out of the atmosphere, where it would otherwise act as a greenhouse gas. The trees use this carbon to grow roots, trunks and leaves, which eventually turn into carbon-rich soil once the tree dies. Significant changes to the forests will translate to changes in global climate. </p>
<p>These forests are warming at rates <a href="https://doi.org/10.1038/s43247-022-00498-3">well above the global average</a>. Rising temperatures directly affect the growth and survival of trees and, in turn, their ability to store carbon.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/557135/original/file-20231101-19-jffqm6.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Graphic showing carbon storage by forest type." src="https://images.theconversation.com/files/557135/original/file-20231101-19-jffqm6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/557135/original/file-20231101-19-jffqm6.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=285&fit=crop&dpr=1 600w, https://images.theconversation.com/files/557135/original/file-20231101-19-jffqm6.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=285&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/557135/original/file-20231101-19-jffqm6.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=285&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/557135/original/file-20231101-19-jffqm6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=358&fit=crop&dpr=1 754w, https://images.theconversation.com/files/557135/original/file-20231101-19-jffqm6.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=358&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/557135/original/file-20231101-19-jffqm6.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=358&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Different forest types around the world store varying amounts of carbon. Warm tropical regions tend to store much more carbon in plants, while cool boreal forests have enormous carbon stores in soil.</span>
<span class="attribution"><a class="source" href="https://www.fs.usda.gov/ccrc/topics/global-carbon">U.S. Forest Service</a></span>
</figcaption>
</figure>
<h2>Forests on the move</h2>
<p>As atmospheric warming frees trees from the icy grip of cold temperatures, adult trees can respond by growing faster. Milder temperatures also allow young seedling trees in the most northern boreal forests to gain a foothold where previous conditions were too harsh for them to become established.</p>
<p>In the warmer, southern boreal forests, the situation is quite different. Here, conditions have become too warm for cold-adapted boreal trees, slowing their growth and even leading to their death. With warming comes dryness, and water stress leaves trees more susceptible to insect infestation and <a href="https://theconversation.com/more-frequent-fires-could-dramatically-alter-boreal-forests-and-emit-more-carbon-122355">fires</a>, as <a href="https://www.cbc.ca/news/science/2024-wildfire-season-el-nino-1.6978559">Canada has experienced in 2023</a> and Siberia in <a href="https://www.vox.com/2019/8/1/20750200/siberia-wildfire-russia-fire-smoke-trump-putin">2019</a> and <a href="https://news.mongabay.com/2020/07/photos-show-scale-of-massive-fires-tearing-through-siberian-forests/">2020</a>. </p>
<p>If this happens at a larger scale, southern boreal forest boundaries will thin and degrade, thereby retreating farther north, where temperatures are still suitable.</p>
<p>If boreal forests expand northward and retreat in the south at the same rates, they could slowly follow warming temperatures. However, our combined research using satellite and field data shows that the story is more complex. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/557275/original/file-20231102-23-r2kfff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Flames and smoke rise above a stretch of conifers." src="https://images.theconversation.com/files/557275/original/file-20231102-23-r2kfff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/557275/original/file-20231102-23-r2kfff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/557275/original/file-20231102-23-r2kfff.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/557275/original/file-20231102-23-r2kfff.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/557275/original/file-20231102-23-r2kfff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/557275/original/file-20231102-23-r2kfff.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/557275/original/file-20231102-23-r2kfff.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Flames from the Donnie Creek wildfire burn along a ridgetop north of Fort St. John, British Columbia, Canada, on July 2, 2023. Fire is part of the ecology of boreal forests, but climate change is drying out trees and making them more fire-prone.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/CanadaWildfiresPhotoGallery/0920472b516345429a090820278d423b/photo">AP Photo/Noah Berger</a></span>
</figcaption>
</figure>
<h2>Tracking forests from space</h2>
<p>Satellites are invaluable for tracking how boreal forests have changed in recent decades and whether these changes are consistent with an overall northward shift. Researchers can use satellites to monitor year-to-year changes in forest characteristics, such as annual tree growth and tree cover.</p>
<p>Our recent studies using satellite data showed that <a href="https://doi.org/10.1111/gcb.16121">tree growth</a> and <a href="https://doi.org/10.1038/s41467-023-39092-2">tree cover</a> increased from 2000 to 2019 throughout much of the boreal forest. These changes occurred mainly in the coldest northern areas. However, there was limited evidence to indicate that forests were expanding past current tree lines.</p>
<p>Our studies also revealed that tree growth and tree cover often decreased from 2000 to 2019 in warmer southern areas of the boreal forests. In these regions, hotter and drier conditions frequently reduced tree growth or killed individual trees, while wildfires and logging contributed to tree cover loss.</p>
<p>Satellite data makes it clear that climate change is affecting both the northern and southern margins of the boreal forest. However, if tree cover loss in the south occurs more rapidly than gains in the north, then the boreal forest will likely contract, rather than simply shifting northward. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/557133/original/file-20231101-25-nw5diu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Satellite map showing gains and losses in North American boreal forest tree cover" src="https://images.theconversation.com/files/557133/original/file-20231101-25-nw5diu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/557133/original/file-20231101-25-nw5diu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=343&fit=crop&dpr=1 600w, https://images.theconversation.com/files/557133/original/file-20231101-25-nw5diu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=343&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/557133/original/file-20231101-25-nw5diu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=343&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/557133/original/file-20231101-25-nw5diu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=432&fit=crop&dpr=1 754w, https://images.theconversation.com/files/557133/original/file-20231101-25-nw5diu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=432&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/557133/original/file-20231101-25-nw5diu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=432&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Satellite measurements show that plant growth widely increased along the cold northern margins of the boreal forest in recent decades, but it often decreased along the warm southern margins − potential early indicators that the boreal forest is beginning to migrate northward.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1111/gcb.16121">Logan Berner, based on results from Berner and Goetz 2022.</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Zooming in to understand forest change</h2>
<p>Forests advance when individual tree seeds germinate and grow, but boreal trees grow slowly and require decades to reach a size that’s visible from space. Finding young trees whose presence would signal tree-line movement requires data from the ground.</p>
<p>In the late 1970s, one of us (David Cooper) documented that young spruce trees were growing at altitudes hundreds of yards higher and locations miles north of the <a href="https://www.jstor.org/stable/40510488">highest-elevation cone-bearing trees</a> in Alaska’s Brooks Range. Returning in 2021, we found those little trees had grown to be several yards tall and were producing cones. More importantly, <a href="https://doi.org/10.1038/s41586-022-05093-2">10 times</a> the number of young spruces now grow above and beyond the tree line than during our first field forays. </p>
<p>Crisscrossing the boundary between Alaska’s boreal forest and its Arctic tundra on foot, we have found thousands of young boreal trees growing <a href="https://doi.org/10.1038/s41586-022-05093-2">up to 25 miles north of established tree lines</a>. Most grow where deeper snows fall, due to an Arctic Ocean version of the “<a href="https://www.weather.gov/safety/winter-lake-effect-snow">lake effect</a>”: Cold air moves across open water, picking up warmth and moisture, which then falls as snow downwind.</p>
<p>Retreating sea ice leaves more open water. This generates stronger winds that propel tree seeds farther and more snowfall that insulates seedlings from harsh winter conditions. The result is that trees in Alaska’s Brooks Range are <a href="https://static-content.springer.com/esm/art%3A10.1038%2Fs41586-022-05093-2/MediaObjects/41586_2022_5093_MOESM5_ESM.gif">rapidly moving into the treeless tundra</a>. However, these rapid expansions are localized and <a href="https://doi.org/10.1111/gcb.15113">do not yet happen everywhere along the northern tree line</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/557270/original/file-20231102-25-zt8dre.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/557270/original/file-20231102-25-zt8dre.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/557270/original/file-20231102-25-zt8dre.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/557270/original/file-20231102-25-zt8dre.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/557270/original/file-20231102-25-zt8dre.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/557270/original/file-20231102-25-zt8dre.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/557270/original/file-20231102-25-zt8dre.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/557270/original/file-20231102-25-zt8dre.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A young white spruce colonist on the Alaskan tundra, with the Brooks Range mountains in the background.</span>
<span class="attribution"><span class="source">Roman Dial</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>The future face of boreal forests</h2>
<p>Our combined research shows that boreal forests are, in fact, responding to rising temperatures. But rapid rates of climatic change mean that trees likely can’t move northward at a pace that keeps up with their loss in the south. </p>
<p>Will trees in the far north ever catch up with climate and prevent forest contraction? At this point, scientists simply don’t know. Perhaps the newly established trees in the Brooks Range herald such an expansion. It’s also unclear whether the northern parts of boreal forests can accumulate enough carbon through increased growth to compensate for carbon losses in the south.</p>
<p>If boreal forests are indeed on the verge of contracting, they will eventually disappear from their current southern edge. This would harm many native and migratory animals, especially birds, by reducing their boreal habitat. The forests also are culturally important to several million people who call them home, such as <a href="https://natural-resources.canada.ca/our-natural-resources/forests/sustainable-forest-management/boreal-forest/8-facts-about-canadas-boreal-forest/17394">Canada’s aboriginal communities</a>.</p>
<p>Monitoring boreal forests around the world more closely, using both satellite data and on-the-ground measurements, will help fill out this picture. Only then can researchers hope to glimpse the future of <a href="https://www.nature.com/articles/d41586-018-07183-6">one of the Earth’s last wildernesses</a>.</p><img src="https://counter.theconversation.com/content/211314/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ronny Rotbarth receives funding from the Dutch Ministry of Education, Culture and Science.</span></em></p><p class="fine-print"><em><span>David J. Cooper receives funding from the National Science Foundation, the US National Park Service, and National Forest Service.</span></em></p><p class="fine-print"><em><span>Logan Berner receives funding from the National Science Foundation and National Aeronautics and Space Administration.</span></em></p><p class="fine-print"><em><span>Roman Dial receives funding from the US National Science Foundation and NASA Alaska Space Grant. </span></em></p>How will Earth’s vast boreal forests look in a warmer world? Combining satellite-based research with fieldwork shows that the planet’s largest wilderness may be changing in unexpected ways.Ronny Rotbarth, Ph.D. Candidate of Arctic and Sub-Arctic Ecology, Wageningen UniversityDavid J. Cooper, Senior Research Scientist Emeritus, Colorado State UniversityLogan Berner, Assistant Research Professor of Global Change Ecology, Northern Arizona UniversityRoman Dial, Professor of Biology and Mathematics, Alaska Pacific UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2108802023-09-29T01:25:27Z2023-09-29T01:25:27ZHere’s how to fix Australia’s approach to soil carbon credits so they really count towards our climate goals<figure><img src="https://images.theconversation.com/files/550802/original/file-20230928-21-n9ydfs.jpg?ixlib=rb-1.1.0&rect=199%2C0%2C9290%2C6331&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/female-farmer-hold-soil-hands-monitoring-2346686237">William Edge, Shutterstock</a></span></figcaption></figure><p>Australia’s plan to achieve <a href="https://www.dcceew.gov.au/climate-change/emissions-reduction/net-zero">net zero</a> greenhouse gas emissions by 2050 relies heavily on carbon credits. </p>
<p>These <a href="https://www.cleanenergyregulator.gov.au/ERF/About-the-Emissions-Reduction-Fund">credits are awarded to projects</a> that avoid the release of greenhouse gases or remove and “sequester” (store) carbon so it’s no longer warming the atmosphere. </p>
<p>Farmers can be awarded credits for <a href="https://www.cleanenergyregulator.gov.au/ERF/Choosing-a-project-type/Opportunities-for-the-land-sector/Agricultural-methods/estimating-soil-organic-carbon-sequestration-using-measurement-and-models-method">increasing soil carbon content</a>. The federal government or companies can then purchase these credits to offset their carbon emissions. </p>
<p>These credits must represent genuine carbon sequestration if they are to mitigate climate change. </p>
<p>As Australian agricultural and soil scientists, we have serious concerns about the way credits are awarded for soil carbon sequestration under the <a href="https://www.cleanenergyregulator.gov.au/OSR/ANREU/types-of-emissions-units/australian-carbon-credit-units">Australian carbon credit unit scheme</a>. There are four main issues with the method that must be addressed as a matter of urgency.</p>
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<figcaption><span class="caption">Soil organic carbon is the treasure beneath our feet (Food and Agriculture Organization of the United Nations)</span></figcaption>
</figure>
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Read more:
<a href="https://theconversation.com/us-scheme-used-by-australian-farmers-reveals-the-dangers-of-trading-soil-carbon-to-tackle-climate-change-161358">US scheme used by Australian farmers reveals the dangers of trading soil carbon to tackle climate change</a>
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<h2>Understanding the carbon cycle</h2>
<p>Much like water, carbon cycles through the environment, moving between plants, the earth and the atmosphere. </p>
<p>Plants take in carbon dioxide from the atmosphere as they grow. The carbon is stored in the plant tissue. When plants die, or drop leaves, this carbon-rich organic matter enters the soil. Then it decomposes, releasing carbon dioxide back into the atmosphere. </p>
<p>When carbon inputs from plants exceed losses from the decomposition of organic matter, the amount of soil carbon increases. That means soil organic carbon is more likely to increase during good seasons when there’s plenty of rainfall available to support plant growth – such as during the recent three-year period of consecutive La Niña events.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Graphic illustrating how carbon cycles through agricultural systems" src="https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=309&fit=crop&dpr=1 600w, https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=309&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=309&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=388&fit=crop&dpr=1 754w, https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=388&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/550131/original/file-20230925-15-sf72i6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=388&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The carbon cycle.</span>
<span class="attribution"><span class="source">Richard Eckard, University of Melbourne</span></span>
</figcaption>
</figure>
<h2>Increases need to be due to management</h2>
<p>The recent <a href="https://www.abc.net.au/news/rural/2023-06-24/aus-farmers-to-earn-money-from-soil-carbon-under-new-methods/102213244">tranche</a> of credits awarded to soil carbon projects raises similar concerns to those that have been raised by experts about <a href="https://theconversation.com/australias-central-climate-policy-pays-people-to-grow-trees-that-already-existed-taxpayers-and-the-environment-deserve-better-186900">credits awarded to trees</a>. Namely, carbon credits are being awarded for changes associated with seasonal conditions (changes that would have happened anyway) rather than human actions.</p>
<p>The current soil carbon method awards credits when an increase in soil organic carbon is detected between two points in time. This is problematic because it can award credits to projects that report increases during relatively wet periods. </p>
<p>This is the case for <a href="https://carbonlink.com.au/wp-content/uploads/CarbonLink-ACCUs-Flow-Media-Release-June-2023-1.pdf">projects sampled in 2021</a>, directly after a period where conditions were unusually favourable for plant growth. That means credits were awarded for sequestration that had more to do with the weather than good management. </p>
<p>Where crediting occurs due to seasonal conditions, the scheme is not providing any true (<a href="https://law.anu.edu.au/sites/all/files/what_the_beare_and_chambers_report_really_found_and_a_critique_of_its_method_16_march_2022.pdf">additional</a>) climate change mitigation. </p>
<h2>Soil carbon can be lost</h2>
<p>Where soil carbon losses are greater than inputs, soil carbon stocks decline and sequestered carbon is released back to the atmosphere. The <a href="https://www.sciencedirect.com/science/article/pii/S0301479720301286">emissions can be rapid</a> and considerable. </p>
<p>Furthermore, modelling indicates it’s likely <a href="https://doi.org/10.1016/j.geoderma.2018.09.041">soil carbon could be lost</a> under the warmer and drier conditions of future climates. </p>
<p>Where a project loses soil carbon, the legislation does not require excess credits to be returned. Rather, a scheme-wide <a href="https://www.cleanenergyregulator.gov.au/ERF/Choosing-a-project-type/Opportunities-for-the-land-sector/Risk-of-reversal-buffer">buffer</a> generated from all sequestration projects covers such losses. </p>
<p>This approach is inequitable because all projects share the same burden of maintaining the buffer, irrespective of the risk of reversal of individual projects. </p>
<h2>Overinflated sequestration rates</h2>
<p>Based on a <a href="https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1002/eap.1473?__cf_chl_tk=1zpwtYjrpjjoZAaRpgcOb5o7R5c_fLaqDx0tadA0kWA-1693540306-0-gaNycGzND1A">comprehensive global analysis</a>, the <a href="https://carbonlink.com.au/wp-content/uploads/CarbonLink-ACCUs-Flow-Media-Release-June-2023-1.pdf">number of carbon credits generated</a> by some Australian projects appears unrealistically high. The most likely reason for these large values is high rainfall, but the way the method works makes it impossible to know for sure because the impacts of management are not identified.</p>
<p>This is not the first time a soil carbon project has made <a href="https://theconversation.com/us-scheme-used-by-australian-farmers-reveals-the-dangers-of-trading-soil-carbon-to-tackle-climate-change-161358">unrealistic claims</a>. </p>
<p>In addition, <a href="https://carbonlink.com.au/wp-content/uploads/CarbonLink-ACCUs-Flow-Media-Release-June-2023-1.pdf">one project saw 44%</a> of the increase in soil carbon at depths below 30cm. This is an issue because published studies show soil carbon changes in deeper soil are <a href="https://www.sciencedirect.com/science/article/pii/S0167880923002785">relatively small</a> and happen slowly. We are concerned the reported changes may have more to do with the way they were calculated. </p>
<p>Currently, data used to calculate credits are not released by the scheme regulator so cannot be scientifically verified. The release of data under strict non-disclosure arrangements would allow scientists to assess the implementation of the method. This would provide confidence credits generated represent real climate change mitigation. </p>
<p>Increased transparency was a <a href="https://www.dcceew.gov.au/sites/default/files/documents/independent-review-accu-exec-summary.pdf">key recommendation</a> of the <a href="https://oia.pmc.gov.au/published-impact-analyses-and-reports/chubb-review-australian-carbon-credit-units">Chubb Review</a> of Australian Carbon Credit Units in 2022. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/chubb-review-of-australias-carbon-credit-scheme-falls-short-and-problems-will-continue-to-fester-197401">Chubb review of Australia's carbon credit scheme falls short – and problems will continue to fester</a>
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<h2>Contributing to our emissions targets?</h2>
<p>Australia’s emissions are reported annually to the United Nations in the national <a href="https://www.dcceew.gov.au/climate-change/publications/national-inventory-reports">greenhouse gas inventory</a>. These annual inventories show progress towards our declared emissions reduction targets. </p>
<p>The current inventory method used to account for changes in soil carbon uses coarse regional-level statistics. Changes to practices at farm level, such as grazing management, are not detected and will not be reflected in our national greenhouse gas accounts. Further, Australia reports changes in soil carbon for the top 30cm of the soil only whereas carbon credits are also awarded for changes that occur deeper in the soil. </p>
<p>This means some soil carbon credits the Australian government purchases do not count toward our emissions targets. It calls into question the effectiveness of using taxpayer funds to purchase soil carbon credits as a policy tool.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australia-relies-on-controversial-offsets-to-meet-climate-change-targets-we-might-not-get-away-with-it-in-egypt-193460">Australia relies on controversial offsets to meet climate change targets. We might not get away with it in Egypt</a>
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<h2>Getting it right</h2>
<p>To address the issues we have identified, the measurement-based soil carbon <a href="https://www.cleanenergyregulator.gov.au/ERF/Choosing-a-project-type/Opportunities-for-the-land-sector/Agricultural-methods/estimating-soil-organic-carbon-sequestration-using-measurement-and-models-method">method</a> needs to be revised to only credit increases due to management. For instance, <a href="https://verra.org/methodologies/vm0042-methodology-for-improved-agricultural-land-management-v2-0/">the Verra scheme</a> in the international voluntary carbon market uses a method that minimises crediting for increases associated with rainfall. </p>
<p>To support revision of Australia’s scheme, scientists should be granted access to project data. Data could to be used to improve models in order to distinguish between climate and management effects. This would ensure the method is fit for purpose. </p>
<p>There also needs to be greater focus on monitoring changes in soil carbon. For a start, Australia’s <a href="https://www.tern.org.au/">Terrestrial Ecosystem Research Network</a> should be extended to include agricultural land. This would provide data to increase transparency, independence and rigour of soil carbon estimates. </p>
<p>The revisions we propose would help ensure investment in carbon credits contributes to our national emissions reduction targets and addresses the urgent challenge of climate change.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-tonne-of-fossil-carbon-isnt-the-same-as-a-tonne-of-new-trees-why-offsets-cant-save-us-200901">A tonne of fossil carbon isn't the same as a tonne of new trees: why offsets can't save us</a>
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<img src="https://counter.theconversation.com/content/210880/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Aaron Simmons is a Senior Research Scientist with the NSW Department of Primary Industries. Aaron has received funding from the Commonwealth and NSW governments for soil carbon research and policy development. </span></em></p><p class="fine-print"><em><span>Annette Cowie is a Senior Principal Research Scientist in the Climate Branch at the NSW Department of Primary Industries, and Adjunct Professor in the School of Environmental and Rural Science at the University of New England. She has received funding for soil carbon research from NSW and Commonwealth government programs. Annette is a member of Soil Science Australia, a not-for-profit, professional association for soil scientists, and on the Advisory Board of Australia New Zealand Biochar Industry Group. </span></em></p><p class="fine-print"><em><span>Dr Beverley Henry is an Adjunct Associate Professor at Queensland University of Technology. She has previously worked for, and received funding from, the Commonwealth and Queensland Governments, and has, or has previously held, science consulting and advisory roles with Australian and international government and agricultural organisations. </span></em></p><p class="fine-print"><em><span>Brian Wilson is a Professor in Terrestrial Carbon Management at the University of New England. He has received funding from the Commonwealth and State Government and from the Cotton Research and Development Corporation for research relevant to soil carbon.</span></em></p><p class="fine-print"><em><span>David Pannell is a professor in environmental economics and agricultural economics at the University of Western Australia. He has received funding from the Commonwealth Government and from Grains Research and Development Corporation for research relevant to soil carbon. </span></em></p><p class="fine-print"><em><span>David Rowlings is a Professor in Sustainable Agriculture at Queensland University of Technology. He receives funding from Meat and Livestock Australia and Department Agriculture, Forestry and Fisheries for soil carbon research. </span></em></p><p class="fine-print"><em><span>Elaine Mitchell is a Research Fellow at the Queensland University of Technology. She has received funding from the Commonwealth Government for soil carbon research. She is also the founder of Ecometric, which provides advisory services in the natural capital space, including advice to carbon project developers on approaches to stratification, soil sampling and soil carbon modelling.
</span></em></p><p class="fine-print"><em><span>Matthew Tom Harrison is an Associate Professor at the University of Tasmania. He has been awarded funding from State and Commonwealth Governments, as well as Research Development Corporations to research practices, skills and technologies for improving soil organic carbon sequestration.</span></em></p><p class="fine-print"><em><span>Peter Grace is Professor Global Change at Queensland University of Technology. He currently receives funding from the Grains Research and Development Corporation, Meat and Livestock Australia, the Dept of Climate Change Energy Environment and Water, National Collaborative Research Infrastructure Scheme - Terrestrial Ecosystem Research Network, AgriFutures, and AgriMix. He has previously received funding from the Clean Energy Regulator, the Dept of Agriculture Fisheries and Forestry, and Cotton Research and Development Corporation.</span></em></p><p class="fine-print"><em><span>Raphael Viscarra Rossel is a Professor of Soil and Landscape Science at Curtin University. Previously, he was a Senior Principal Research Scientist at CSIRO, where he received funding from the Commonwealth Government for developing innovative soil carbon measurement methods that aided the formulation of the soil carbon methodology.</span></em></p><p class="fine-print"><em><span>Richard Eckard receives funding from Meat and Livestock Australia and the Commonwealth of Australia on greenhouse gas emissions from agriculture and carbon farming. His science contributed to six Australian carbon credit methods. </span></em></p><p class="fine-print"><em><span>Warwick Badgery is a Research Leader with the NSW Department of Primary Industries and is an Honorary Senior Fellow at Melbourne University. He receives funding from Meat and Livestock Australia, the NSW and Federal Governments for research on climate mitigation and soil carbon. </span></em></p>A group of agricultural and soil scientists has serious concerns about the way credits are awarded for soil carbon sequestration in Australia.Aaron Simmons, Adjunct Senior Research Fellow, University of New EnglandAnnette Cowie, Adjunct Professor, University of New EnglandBeverley Henry, Adjunct Associate Professor, Queensland University of TechnologyBrian Wilson, Professor, University of New EnglandDavid Pannell, Director, Centre for Environmental Economics and Policy, The University of Western AustraliaDavid Rowlings, Professor, Queensland University of TechnologyElaine Mitchell, Research Fellow, Queensland University of TechnologyMatthew Tom Harrison, Associate Professor of Sustainable Agriculture, University of TasmaniaPeter Grace, Professor of Global Change, Queensland University of TechnologyRaphael Viscarra Rossel, Professor of Soil & Landscape Science, Curtin UniversityRichard Eckard, Professor & Director, Primary Industries Climate Challenges Centre, The University of MelbourneWarwick Badgery, Research Leader Pastures an Rangelands, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2056392023-06-08T03:12:15Z2023-06-08T03:12:15ZBlue carbon: could a solution to the climate challenge be buried in the depths of fiords?<figure><img src="https://images.theconversation.com/files/530747/original/file-20230608-22-c17hwb.jpeg?ixlib=rb-1.1.0&rect=0%2C394%2C4685%2C2487&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Rebecca McLeod</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Cyclone Gabrielle has highlighted forestry slash as a problematic aspect of relying on plantation forests to draw down carbon dioxide (CO₂) from the atmosphere. </p>
<p>While we no doubt must prioritise reducing emissions, we will have to find other effective methods of CO₂ removal. This includes protecting and restoring natural carbon sinks. </p>
<p>Aotearoa New Zealand is a maritime nation with 94% of the continent of Zealandia under water. Marine sediments provide the <a href="https://www.frontiersin.org/articles/10.3389/fmars.2020.00165/full">largest store of organic carbon on Earth</a>, so why aren’t we looking to the sea as we plan our way out of the climate crisis?</p>
<p>The concept of blue carbon (carbon captured by the marine environment) was coined around <a href="https://royalsocietypublishing.org/doi/epdf/10.1098/rsbl.2018.0781">15 years ago</a>. But it is only this week, as the UN Framework Convention on Climate Change (<a href="https://unfccc.int/process-and-meetings/what-is-the-united-nations-framework-convention-on-climate-change">UNFCCC</a>) meets in Germany in preparation for the next climate summit in November, that blue carbon is emerging as a mainstream global option for carbon sequestration and accounting. </p>
<p>Blue carbon opportunities are varied, but it makes sense to focus first on the most productive marine carbon sinks. Research shows that fiords in temperate areas such as New Zealand’s <a href="https://www.otago.ac.nz/research/centres/otago0241619.html">Fiordland</a> and in <a href="https://www.bluecarbon.scot/">Scotland</a> have some of the highest potential for carbon storage. </p>
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<h2>The emergence of blue carbon solutions</h2>
<p>New Zealand’s Climate Change Commission recently released its <a href="https://www.climatecommission.govt.nz/our-work/advice-to-government-topic/advice-for-preparation-of-emissions-reduction-plans/2023-draft-advice-to-inform-the-strategic-direction-of-the-governments-second-emissions-reduction-plan-april-2023/">draft advice</a> to inform the strategic direction of the government’s second emissions reduction plan, covering the 2026–2030 emissions budget. </p>
<p>In terms of carbon removals, we see heavy reliance on exotic pine forestry, despite the limitation that carbon held in production forests is only stored for as long as the trees remain standing or the products made from them endure. Forestry planting is also limited by availability of land. </p>
<p>Blue carbon opportunities range from the restoration of wetlands to seaweed farming. They differ markedly in the scientific understanding of the rate and permanence of carbon sequestration – and how ready they are to be <a href="https://www.frontiersin.org/articles/10.3389/fmars.2022.851448/full">developed into climate change policy</a>. The challenge lies in reliably measuring where and how fast carbon is being stored long term. </p>
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<p>This can prove particularly challenging in scenarios where the place of carbon deposition (such as deep ocean sediments) is far removed from the place of carbon capture (the surface waters where photosynthesis occurs). </p>
<p>While there is growing international recognition that natural carbon stores should be protected, governments are particularly interested in management actions that lead to increased carbon capture and long-term storage. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-change-why-we-cant-rely-on-regrowing-coastal-habitats-to-offset-carbon-emissions-185726">Climate change: why we can't rely on regrowing coastal habitats to offset carbon emissions</a>
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<p>Such efforts, including the planting of mangrove forests in the tropics, need to reliably demonstrate “additionality” (more carbon being sequestered) and “permanence”. These verification requirements have slowed large-scale investment. </p>
<figure class="align-center ">
<img alt="Mitre Peak in Milford Sound" src="https://images.theconversation.com/files/530726/original/file-20230607-28-g6vrht.jpg?ixlib=rb-1.1.0&rect=13%2C54%2C2989%2C1751&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/530726/original/file-20230607-28-g6vrht.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/530726/original/file-20230607-28-g6vrht.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/530726/original/file-20230607-28-g6vrht.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/530726/original/file-20230607-28-g6vrht.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/530726/original/file-20230607-28-g6vrht.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/530726/original/file-20230607-28-g6vrht.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Fiords in temperate regions may account for 11% of the global marine organic carbon burial.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Fiords are hotspots for carbon burial</h2>
<p>The first blue carbon initiatives included coastal wetlands like mangrove forests and salt marshes. They were incorporated into carbon accounting under the UNFCCC in <a href="https://www.ipcc.ch/publication/2013-supplement-to-the-2006-ipcc-guidelines-for-national-greenhouse-gas-inventories-wetlands/">2013</a>. But the coastal and deeper ocean also offer carbon sequestration opportunities.</p>
<p>It is <a href="https://www.frontiersin.org/articles/10.3389/fmars.2020.00165/full">well established</a> that organic carbon that settles to the seafloor and is quickly buried can result in long-term storage. Some aquatic environments are hotspots for carbon burial. Fiords in temperate areas, such as in Fiordland, are among the hottest of hotspots, <a href="https://www.nature.com/articles/ngeo2421">burying the largest amount of organic carbon per area</a> in the world.</p>
<p>Fiords occupy less than 0.1% of Earth’s surface, but <a href="https://www.nature.com/articles/ngeo2433">researchers estimate</a> they account for 11% of global marine organic carbon burial. In Fiordland, this process is amplified because additional organic material from the rainforest is deposited into the fiords and quickly sinks to deep low-oxygen environments where it is preserved. </p>
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Read more:
<a href="https://theconversation.com/from-mangroves-to-fjords-coastal-ecosystems-can-take-up-or-emit-greenhouse-gases-but-globally-theyre-a-vital-sink-205473">From mangroves to fjords, coastal ecosystems can take up or emit greenhouse gases. But globally, they're a vital sink</a>
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<p>A recent estimate of New Zealand’s carbon budget derived from <a href="https://acp.copernicus.org/articles/17/47/2017/">atmospheric measurements and modelling</a> found Fiordland’s carbon sink is larger than previously thought. It could potentially offset 10-20% of New Zealand’s annual greenhouse gas emissions. </p>
<p>Although Fiordland has a high level of protection, we don’t yet know whether there are human actions (for example, <a href="https://www.stuff.co.nz/environment/130064601/will-climate-change-impact-on-fiordlands-carbon-sink?utm_source=dlvr.it&utm_medium=twitter">freshwater input from electricity generation</a>) that have altered the capacity of this massive carbon sink. </p>
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<p>We also suspect the remarkable capacity of fiords to lock away carbon could be at risk in the future as the climate continues to change. Parts of Fiordland could lock away less carbon, or worse, switch from being carbon stores to carbon sources. </p>
<h2>Looking to Scotland for leadership</h2>
<p>Scotland is leading the way in the blue carbon space, having established a blue carbon forum in 2018 that facilitates science and policy development. </p>
<p>The growing global awareness of fiords as important blue carbon systems points to a new “fiord nations” partnership that could encourage stock assessments. </p>
<p>The Scottish government’s <a href="https://www.gov.scot/news/agreement-with-scottish-green-party/">Bute House Agreement</a> (2021) includes a commitment to protect 10% of Scotland’s seas under Highly Protected Marine Area (<a href="https://www.gov.uk/government/publications/highly-protected-marine-areas/highly-protected-marine-areas-hpmas">HPMA</a>) designations. In a radical step, blue carbon potential is part of the selection of these HPMA sites. </p>
<p>Scottish sea lochs (or fiords) meet many of the criteria for HPMA designation, including their unique marine ecosystems and organic-rich sediments. This highlights a global leadership opportunity, where the protection of blue carbon hotspots might help change our appreciation of the growing pressures these forgotten seascapes are facing.</p>
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Read more:
<a href="https://theconversation.com/seagrass-meadows-shrank-by-92-in-uk-waters-restoring-them-could-absorb-carbon-emissions-and-boost-fish-156459">Seagrass meadows shrank by 92% in UK waters - restoring them could absorb carbon emissions and boost fish</a>
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<p>Under the Paris Agreement, countries regularly make climate pledges, known as Nationally Determined Contributions (<a href="https://unfccc.int/process-and-meetings/the-paris-agreement/nationally-determined-contributions-ndcs">NDCs</a>). They give a good sense of how ambitious each country is. </p>
<p>The UK’s latest NDC (2022) paints a comprehensive picture of aspirations for improving marine management in accordance with their <a href="https://moat.cefas.co.uk/introduction-to-uk-marine-strategy/">marine strategy</a> to improve carbon sequestration and biodiversity. Indeed, Scotland published its own “indicative” NDC in 2021, in which it highlighted the potential for blue carbon. </p>
<p><a href="https://unfccc.int/sites/default/files/NDC/2022-06/New%20Zealand%20NDC%20November%202021.pdf">New Zealand’s NDC</a>, updated in 2021, dedicates just one sentence to the ocean, stating it “looks forward to considering” new methodologies regarding wetlands over time. </p>
<p>New Zealand does not yet have a marine policy. But the enormous potential of our seas and, specifically fiords, to <a href="https://news.clas.ufl.edu/coastal-ecosystems-store-greenhouse-gases-shows-role-of-salt-marshes-fjords/">sequester carbon</a> is becoming apparent. We could be doing so much more to understand, protect and restore parts of our coastline and seafloor that sequester carbon, potentially delivering benefits for climate, a sustainable blue economy and marine life.</p><img src="https://counter.theconversation.com/content/205639/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rebecca J McLeod receives funding from the Ministry of Business Innovation and Employment (Endeavour Fund). She is the Chairperson of the Fiordland Marine Guardians. </span></em></p><p class="fine-print"><em><span>William Austin does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Marine sediments are the world’s largest store of carbon, and fiords in particular are a massive sink. But New Zealand doesn’t even have an oceans policy to develop blue carbon climate policy.Rebecca J McLeod, Senior Research Fellow in Marine Ecology, University of OtagoWilliam Austin, Professor in marine geology, University of St AndrewsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2054892023-06-05T00:35:57Z2023-06-05T00:35:57ZWhale of a tale? The stories about whales helping tackle climate change are overblown<figure><img src="https://images.theconversation.com/files/528764/original/file-20230529-27-ljklvc.jpg?ixlib=rb-1.1.0&rect=6%2C6%2C4576%2C3037&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Whales have long fascinated us with their size and beauty. Once we stopped whaling, their populations have begun to recover, in a major win for conservation. </p>
<p><a href="https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/130220">Research</a> has suggested healthy whale populations could help us in unexpected ways – by storing carbon for the long term. </p>
<p>How? Whales are usually huge. Among their number is the blue whale, the largest animal ever to have lived. At up to 30 metres long and 190 tonnes, they’re bigger than any dinosaur. This gives these mega-mammals an oversized role in the oceans. Their plumes of poo contains so many nutrients that phytoplankton blooms can form in its wake. These tiny photosynthesising creatures soak up carbon dioxide in their bodies. When they die, they can sink to the bottom and be covered in sediment, storing the carbon. </p>
<p>As we look desperately for good news on climate amid the accelerating crisis, whales seemed to offer one. Bring back the whales, store more carbon naturally. </p>
<p>But this is premature, as our <a href="https://www.frontiersin.org/articles/10.3389/fmars.2023.1117409/abstract">new research</a> points out. This area is riddled with uncertainties and a lack of data. While the story sounds good, we simply cannot say more whales means more carbon storage at this point. If we focus on unproven measures like encouraging whale populations, we risk taking attention away from proven climate measures such as steadily reducing emissions from fossil fuel burning or protecting our stores of blue carbon in mangroves and seagrass meadows. </p>
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<a href="https://images.theconversation.com/files/527709/original/file-20230523-17-xg693v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/527709/original/file-20230523-17-xg693v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/527709/original/file-20230523-17-xg693v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=461&fit=crop&dpr=1 600w, https://images.theconversation.com/files/527709/original/file-20230523-17-xg693v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=461&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/527709/original/file-20230523-17-xg693v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=461&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/527709/original/file-20230523-17-xg693v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=579&fit=crop&dpr=1 754w, https://images.theconversation.com/files/527709/original/file-20230523-17-xg693v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=579&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/527709/original/file-20230523-17-xg693v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=579&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Whale poo floating on the surface in Antarctica.</span>
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<h2>Why has there been so much focus on whales?</h2>
<p>The climate crisis is intensifying. Our first year with over 1.5°C of heating could come <a href="https://theconversation.com/global-warming-to-bring-record-hot-year-by-2028-probably-our-first-above-1-5-c-limit-205758">within five years</a>. Given this, governments and researchers are looking for ways to tackle this global crisis by using nature to draw CO₂ back out of the air. </p>
<p>Trees and peatlands are natural carbon sinks. So is the <a href="https://www.nature.com/articles/s41558-021-01089-4">‘blue carbon’</a> stored in mangroves and seagrass meadows for thousands of years.</p>
<p>So why not whales? In recent years, there’s been <a href="https://theconversation.com/oceans-and-their-largest-inhabitants-could-be-the-key-to-storing-our-carbon-emissions-180901">mounting enthusiasm</a> about whales – any marine animal able to boost phytoplankton growth is arguably adding to natural ways to store carbon. </p>
<p>Here’s how the chain of events would work. As whales feed and migrate, they pump large amounts of nutrients between different parts of the oceans and different depths – mainly through their poo. They also act as a conveyor belt, taking nutrients between different oceans. One species, the gray whale, is the <a href="https://www.guinnessworldrecords.com/world-records/632373-largest-animal-bioturbator#:%7E:text=Bioturbators%20are%20considered%20%22eco%20engineers,native%20to%20the%20Pacific%20Ocean.">largest animal</a> involved in bioturbation, meaning they churn up sediment as they gouge the seafloor hunting shrimp. </p>
<p>These roles make whales ecosystem engineers. Their activities are significant enough to shape local ecosystems where they feed and fertilise the surface of the ocean through defecation. Whale poo, in particular, looks to have a significant effect on phytoplankton growth, especially in the Southern Ocean. </p>
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<a href="https://images.theconversation.com/files/528763/original/file-20230529-19-x9rrqe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="sperm whale pooing" src="https://images.theconversation.com/files/528763/original/file-20230529-19-x9rrqe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/528763/original/file-20230529-19-x9rrqe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=329&fit=crop&dpr=1 600w, https://images.theconversation.com/files/528763/original/file-20230529-19-x9rrqe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=329&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/528763/original/file-20230529-19-x9rrqe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=329&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/528763/original/file-20230529-19-x9rrqe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=413&fit=crop&dpr=1 754w, https://images.theconversation.com/files/528763/original/file-20230529-19-x9rrqe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=413&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/528763/original/file-20230529-19-x9rrqe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=413&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">A whale pooing is quite an event, as this sperm whale shows. But is it enough to make a difference on an ecosystem scale?</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>Fish and other marine species <a href="https://www.science.org/doi/10.1126/sciadv.abb4848">also contribute</a> to the biological carbon pump. In this process, CO₂ is stored in organic matter through photosynthesis and washed into the deeper ocean where some is stored for long periods of time. </p>
<p>Whales could also potentially capture carbon in other ways: in their flesh, where they keep it for their long lifespans, and when a whale falls and sinks to the bottom, where it might be covered in sediment. </p>
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<a href="https://images.theconversation.com/files/528843/original/file-20230529-29-n3ci3n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/528843/original/file-20230529-29-n3ci3n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/528843/original/file-20230529-29-n3ci3n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=382&fit=crop&dpr=1 600w, https://images.theconversation.com/files/528843/original/file-20230529-29-n3ci3n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=382&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/528843/original/file-20230529-29-n3ci3n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=382&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/528843/original/file-20230529-29-n3ci3n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=480&fit=crop&dpr=1 754w, https://images.theconversation.com/files/528843/original/file-20230529-29-n3ci3n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=480&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/528843/original/file-20230529-29-n3ci3n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=480&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">These are the five main pathways through which whales might contribute to carbon sequestration.</span>
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<h2>So why should we be sceptical?</h2>
<p>While it’s entirely possible whales can help sequester carbon, they are likely to make only a limited contribution. </p>
<p>Research in this area is challenging, with many complexities and uncertainties. How do you measure a whale’s lifetime contribution? We’ll need more research to find out either way. </p>
<p>For now, <a href="https://www.frontiersin.org/articles/10.3389/fmars.2022.781876/full">what we do know</a> suggests blue carbon in mangroves, salt marshes and seagrasses is well beyond what large whales contribute to carbon storage. </p>
<p>For us to conclusively say whales can play a role in reducing CO₂ concentration in the atmosphere, we’d need to be able to trace a clear link between how they influence the biological carbon pump, with more whales leading to more organic carbon heading from the surface into the deep ocean, and how much of this then enters longer-term storage in sediments. </p>
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<img alt="" src="https://images.theconversation.com/files/527724/original/file-20230523-19-jbrgyp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/527724/original/file-20230523-19-jbrgyp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=433&fit=crop&dpr=1 600w, https://images.theconversation.com/files/527724/original/file-20230523-19-jbrgyp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=433&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/527724/original/file-20230523-19-jbrgyp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=433&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/527724/original/file-20230523-19-jbrgyp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=544&fit=crop&dpr=1 754w, https://images.theconversation.com/files/527724/original/file-20230523-19-jbrgyp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=544&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/527724/original/file-20230523-19-jbrgyp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=544&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Whales are big. But we don’t know enough to say they’re good at storing carbon. This image shows a humpback whale feeding in Antarctic waters.</span>
<span class="attribution"><span class="source">Lauren Harrell</span></span>
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<p>What we know about the way the oceans respond to carbon dioxide add further weight to whale scepticism. Of the carbon dioxide we emitted between 2009 and 2018, about 40% stayed in the atmosphere, 29% was soaked up by land ecosystems and 23% was absorbed by the oceans, largely due to the tireless photosynthesising of phytoplankton. The cold Southern Ocean is the major contributor among the oceans, accounting for 40% of all ocean absorption. </p>
<p>Zoomed out, all the world’s oceans <a href="https://essd.copernicus.org/articles/14/4811/2022/">take up</a> an estimated 53 billion tonnes of carbon annually. Of this, 4 billion tonnes of organic matter sinks below the surface. But only 1% of this actually gets stored in sea floor sediment for the long term. </p>
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<strong>
Read more:
<a href="https://theconversation.com/bottoms-up-how-whale-poop-helps-feed-the-ocean-27913">Bottoms up: how whale poop helps feed the ocean</a>
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<p>So when we look at the five ways whales could boost carbon removal, the most important one is through their huge poos, which can trigger plankton growth. The “whale pump” is also driven by their poo, and when gray whales or other species turn over sediment, it only has a local effect. When a dead whale falls to the seafloor and is eaten, some carbon may be stored long term if its bones are buried. But it’s unlikely to be a significant amount. </p>
<p>In short, we don’t know enough to say whales help carbon storage – and what we do know suggests the opposite. </p>
<h2>Whales are more than their carbon</h2>
<p>Whales are valuable for much more than their role in carbon cycles. They’re celebrated in cultures around the world. They support local economies through industries like whale-watching. Whales host many other species on them, provide a vital food source for deep-sea life when they die, and act as <a href="https://theconversation.com/what-whales-and-dolphins-can-tell-us-about-the-health-of-our-oceans-84169">an indicator</a> of ocean health. </p>
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<img alt="" src="https://images.theconversation.com/files/527719/original/file-20230523-17-upa5ii.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/527719/original/file-20230523-17-upa5ii.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=427&fit=crop&dpr=1 600w, https://images.theconversation.com/files/527719/original/file-20230523-17-upa5ii.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=427&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/527719/original/file-20230523-17-upa5ii.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=427&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/527719/original/file-20230523-17-upa5ii.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=537&fit=crop&dpr=1 754w, https://images.theconversation.com/files/527719/original/file-20230523-17-upa5ii.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=537&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/527719/original/file-20230523-17-upa5ii.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=537&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Whale watching in Australia.</span>
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<p>And while some species hard-hit by whaling are now recovering, many whales face a very uncertain future in a quickly heating ocean. </p>
<p>Whales are unlikely to protect us from climate change. It’s more likely we’ll have to save them. </p>
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Read more:
<a href="https://theconversation.com/sea-creatures-store-carbon-in-the-ocean-could-protecting-them-help-slow-climate-change-108872">Sea creatures store carbon in the ocean – could protecting them help slow climate change?</a>
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<img src="https://counter.theconversation.com/content/205489/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Olaf Meynecke receives funding from a private charitable fund as part of the Whales and Climate Program. </span></em></p>We want good news on climate change. But whales storing enough carbon needs more evidence.Olaf Meynecke, Research Fellow in Marine Science, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2028162023-04-20T16:39:40Z2023-04-20T16:39:40ZUp in smoke: Human activities are fuelling wildfires that burn essential carbon-sequestering peatlands<figure><img src="https://images.theconversation.com/files/518523/original/file-20230330-130-461u7j.jpg?ixlib=rb-1.1.0&rect=175%2C117%2C4661%2C3136&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Smouldering fire in a drained peatland near Fort McMurray, Alta. produces smoke from underground. These ecosystems are affected by rising temperatures, drought, wildfire and various human actions including drainage.</span> <span class="attribution"><span class="source">(Leyland Cecco)</span>, <span class="license">Author provided</span></span></figcaption></figure><p>For centuries, society has scorned bogs, fens and swamps — collectively known as peatlands — <a href="https://www.iucn.org/resources/issues-brief/peatlands-and-climate-change#:%7E:text=">treating them as wastelands</a> available to be drained and developed without realizing they’re important buffers against climate-changing carbon emissions.</p>
<p>It’s only recently that humans have realized how vital these wetlands are to regulating our climate, despite negative connotations in derisive expressions like “swamped,” “bogged down” and “drain the swamp.” </p>
<p>Draining the swamp, wherever it might be, could be a catastrophic mistake for humankind as climate change throws punches that these ecosystems can handle much better than others.</p>
<p>But as the changing climate exacerbates the extent of droughts and wildfires, especially in the vast peatlands of the north, these ecosystems are now fighting a losing battle. </p>
<h2>Threats to carbon-sequestering peatlands</h2>
<p><a href="https://peatlands.org/peatlands/what-are-peatlands/">A majority of all the world’s peatlands</a> are found in northern regions. Layered by waterlogged peat topped by living mosses, these peatlands absorb and expel carbon, typically storing a little more than they give off, making them <a href="https://www.clientearth.org/latest/latest-updates/stories/what-is-a-carbon-sink/#:%7E:text=A%20carbon%20sink%20is%20anything,fossil%20fuels%20or%20volcanic%20eruptions.">carbon sinks</a> over time. Over thousands of years, they have stockpiled massive amounts of carbon. </p>
<figure class="align-center ">
<img alt="A wetland photographed from above." src="https://images.theconversation.com/files/521996/original/file-20230420-2772-4p6gj1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/521996/original/file-20230420-2772-4p6gj1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=331&fit=crop&dpr=1 600w, https://images.theconversation.com/files/521996/original/file-20230420-2772-4p6gj1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=331&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/521996/original/file-20230420-2772-4p6gj1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=331&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/521996/original/file-20230420-2772-4p6gj1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=416&fit=crop&dpr=1 754w, https://images.theconversation.com/files/521996/original/file-20230420-2772-4p6gj1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=416&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/521996/original/file-20230420-2772-4p6gj1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=416&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Over thousands of years, peatlands have accumulated massive amounts of carbon.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Collectively, peatlands hold more carbon than all the world’s forests. <a href="https://www.unep.org/news-and-stories/press-release/global-assessment-reveals-huge-potential-peatlands-climate-solution">Peatlands account for just three per cent of the world’s land mass</a> but hold about a third of the planet’s stored soil carbon, making them Earth’s most carbon-dense ecosystems.</p>
<p>However, peatlands are under pressure everywhere. They are affected by rising temperatures, drought, wildfire and various human actions, including drainage. In this <a href="https://peatmoss.com/peat-moss-harvesting/">process of draining</a>, the water from the peatlands is allowed to run off through dug-out ditches, thus making the wetland drier. </p>
<p>Individual bogs are drained for agriculture, mining, urban development, wind turbine placement or peat harvesting. So far, between <a href="https://www.nature.com/articles/s41467-018-03406-6">seven and 10 per cent</a> of all northern peatlands have been drained.</p>
<h2>Fire and bogs</h2>
<p>Wildfires are becoming <a href="https://doi.org/10.1111/gcb.16006">more frequent and more severe</a>, meaning peatlands will have to be at their best to continue absorbing carbon. </p>
<p>Healthy peatlands are remarkably <a href="https://doi.org/10.1002%2Fece3.9912">resilient to the impacts of fire</a>. A significant amount of carbon is lost both to burning itself and through burn damage that impairs the growth of carbon-sequestering mosses. But these ecosystems are typically able to recover and restore their climate-regulating function within 10 to 30 years. </p>
<p>However, when bogs have been damaged, especially by drainage, they become vulnerable to wildfire.</p>
<p>Even without fire, drained bogs are net contributors of carbon. When they burn, they <a href="https://doi.org/10.1088/1748-9326/aaa136">burn much more deeply</a> because their peat reserves are dry and dense. These self-propagating smouldering fires can spew millions of tonnes of carbon and harmful, <a href="https://doi.org/10.1097%2FEDE.0000000000000090">toxic smoke</a> into our atmosphere. </p>
<h2>The time to save our peatlands is now</h2>
<p>As climate change accelerates over the coming decades, the interplay between degraded peatlands and hotter fires significantly changes the carbon equation in the environment.</p>
<figure class="align-center ">
<img alt="Burned trees and grasses stand out from the stunted greenery in a peatland" src="https://images.theconversation.com/files/281798/original/file-20190628-94720-1ascytm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/281798/original/file-20190628-94720-1ascytm.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281798/original/file-20190628-94720-1ascytm.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281798/original/file-20190628-94720-1ascytm.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281798/original/file-20190628-94720-1ascytm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281798/original/file-20190628-94720-1ascytm.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281798/original/file-20190628-94720-1ascytm.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A burned peatland in the Fort McMurray wildfire. It is critical to keep our peatlands from burning up,</span>
<span class="attribution"><span class="source">(Mike Waddington)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In our <a href="https://www.nature.com/articles/s41558-023-01657-w">recently published paper</a>, we found that the direct threat from drainage, coupled with climate-change enhanced wildfires, is accelerating the release of carbon from these peatlands. Simply put, our actions are turning climate-friendly peatlands into liabilities, with potentially devastating consequences.</p>
<p>Our study of natural, degraded and restored forms of peatlands in boreal and temperate regions revealed that the once stable carbon-storing power of our northern peatlands is gradually losing to the effects of fire, and drained peatlands are the biggest culprits for this. </p>
<p>Compromising the healthy peatlands that remain — even if it’s for otherwise beneficial uses such as growing food or helping us move away from fossil fuels — could backfire badly, especially as climatic conditions worsen.</p>
<figure class="align-right ">
<img alt="A woman stands next to a pile of moss that remains unaffected by fire." src="https://images.theconversation.com/files/280559/original/file-20190620-149810-e6ac54.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/280559/original/file-20190620-149810-e6ac54.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/280559/original/file-20190620-149810-e6ac54.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/280559/original/file-20190620-149810-e6ac54.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/280559/original/file-20190620-149810-e6ac54.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/280559/original/file-20190620-149810-e6ac54.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/280559/original/file-20190620-149810-e6ac54.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Sophie Wilkinson demonstrates the resistance of moss to an experimental fire in a bog during a project conducted in partnership with FP Innovations, Alberta Agriculture and Forestry and the Canadian Forest Service.</span>
<span class="attribution"><span class="source">(Greg Verkaik)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We found that without deliberate restoration efforts for already drained peatlands, and protection for those that remain, our carbon-collecting northern bogs could flip to carbon contributors by the end of this century. This will further accelerate the overall pace of global warming and climate change.</p>
<p>Fire is natural, of course, and some peat will always burn, but the degree and frequency of wildfire is making it harder for peatlands to recover their ability to store carbon after a fire. </p>
<p>Our research shows that it is not only critical to keep our peatlands from burning up, but that there is also an important and viable opportunity to mitigate this impending disaster. But the window for action is shrinking quickly. </p>
<p><a href="https://thenarwhal.ca/opinion-peatland-canada-natural-disasters/">Canada is home to one-third of the world’s northern peatlands </a> and a proven force in restoring drained bogs. </p>
<p>The looming peat fire crisis demands that Canada prioritize protecting its intact peatlands and accelerate their restoration. Reviving the carbon-storing capacity of peatlands would delay their broader conversion from climate benefactors to liabilities, providing precious time to act on climate change.</p><img src="https://counter.theconversation.com/content/202816/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sophie Wilkinson receives funding from the Natural Sciences and Engineering Research Council of Canada. </span></em></p><p class="fine-print"><em><span>Mike Waddington receives funding from the Natural Sciences and Engineering Research Council of Canada, Blazing Star Environmental, McMaster University, Ganawenim Meshkiki, and Henvey Inlet Wind LP.</span></em></p>New research shows that northern peatlands may not help regulate our climate by the end of the century.Sophie Wilkinson, Assistant professor, Resource and Environmental Management, Simon Fraser UniversityMike Waddington, Professor, School of Earth, Environment & Society, McMaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2014592023-03-10T03:27:04Z2023-03-10T03:27:04ZCan seaweed save the world? Well it can certainly help in many ways<figure><img src="https://images.theconversation.com/files/514619/original/file-20230310-14-t58ci.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Cayne Layton</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Seaweed is increasingly seen as a solution to many of the world’s most pressing problems. Interest in farming seaweed has exploded. </p>
<p>There’s such a wide range of applications, from fertilisers to foods, bioplastics, textiles, supplements and carbon sinks. It’s hard to think of another substance with so much potential. </p>
<p>Can seaweed save the world? It’s a question being posed this weekend at the WOMADelaide world music festival <a href="https://www.womadelaide.com.au/lineup/the-planet-talks">Planet Talks</a>. I’m on the panel and the answer, I think, is a definite maybe! </p>
<p>I’ve studied seaweeds as ecosystem health indicators for years. I became interested in using seaweed to clean up nutrients in our coastal systems. Now at the Marine Bioproducts Cooperative Research Centre, my eyes have opened to the huge diversity of Australian seaweeds and their many amazing applications.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/ever-heard-of-ocean-forests-theyre-larger-than-the-amazon-and-more-productive-than-we-thought-190534">Ever heard of ocean forests? They're larger than the Amazon and more productive than we thought</a>
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</em>
</p>
<hr>
<h2>A marvelous multitool</h2>
<p>Seaweed is a catch-all term for marine plants. These are the primary producers in our marine and aquatic systems. </p>
<p>In many ways, they’re as diverse as the plants you see on land. Many are foundational species that act like forests underwater, but they come in many different types and forms. We group them into reds, greens and browns. And they have very different properties, just like terrestrial plants, depending on the species and where they live.</p>
<p>It’s true that seaweed has huge potential to address some of the most wicked problems facing the planet. If we were to think of seaweed as one of the tools in the toolbox, they’d be the multitool or Swiss army knife with a wide range of potential applications, including:</p>
<ul>
<li><p>reducing methane production in cows and other ruminants such as goats and sheep </p></li>
<li><p>capturing and storing carbon dioxide</p></li>
<li><p>boosting protein and nutrients in food products </p></li>
<li><p>providing extra health benefits in new therapeutics </p></li>
<li><p>soaking up excess nutrients in wastewater </p></li>
<li><p>creating new materials such as bioplastics, packaging and textiles.</p></li>
</ul>
<p>Another thing that blows me away with seaweed is that one plant can actually tap into several of these market opportunities. So you could be growing it as a nutraceutical supplement, a fibre for textiles and as a fertiliser, all at once. That’s really exciting because it’s not something many of our traditional farming approaches have been able to do.</p>
<h2>Not without its challenges</h2>
<p>Early studies suggested that <a href="https://www.nature.com/articles/s41893-021-00773-9">scaling up seaweed aquaculture</a> could make a big difference to climate change by capturing carbon dioxide emissions. But it turns out it’s <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/jpy.13249">not as simple</a> as that. </p>
<p>Verifying whether the carbon dioxide fixed by seaweeds through photosynthesis can be locked up long-term is extremely complex. There are differences between species and ecosystems. And research has to factor in the interactions of the various organisms that live on and around seaweed communities, as well as the prevailing environmental conditions. </p>
<p>In some situations, seaweed ecosystems <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/jpy.13249">produce more carbon</a> than they can <a href="https://academic.oup.com/icesjms/article/79/3/585/6525671?login=true">capture</a>. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/kelp-wont-help-why-seaweed-may-not-be-a-silver-bullet-for-carbon-storage-after-all-178018">Kelp won't help: why seaweed may not be a silver bullet for carbon storage after all</a>
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</em>
</p>
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<p>However, seaweeds may still have a contribution in this space through carbon offsets. As they can be used to make new products to replace other materials that have larger carbon footprints. This includes new foods, new materials such as fabrics, and new building supplies designed to <a href="https://www.tandfonline.com/doi/full/10.1080/23308249.2022.2048792">store carbon in the long term</a>.</p>
<h2>Cutting methane emissions and other benefits</h2>
<p>The native Australian red seaweed <em>Asparagopsis</em> has been shown to markedly reduce methane production in cattle, when <a href="https://www.sciencedirect.com/science/article/pii/S0959652622001421">added to their diet</a>.</p>
<p>Methane is a potent greenhouse gas that contributes to global warming. It accounts for <a href="https://www.epa.gov/snep/agriculture-and-aquaculture-food-thought">20-30% of all greenhouse gas emissions</a>, much of it associated with livestock production.</p>
<p>Any significant reduction in methane production “would have a rapid and significant effect on atmospheric warming potential”, according to a <a href="https://www.epa.gov/snep/agriculture-and-aquaculture-food-thought">report</a> from the US Environmental Protection Agency. </p>
<p>At the most recent global climate meeting, COP26, it was clearly noted that current national climate commitments will not be enough to avoid exceeding 1.5°C of warming. So we need new and radical solutions. If <em>Asparagopsis</em> farming lives up to its potential, it could make a truly meaningful difference.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/514617/original/file-20230310-440-eiamcv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A man holds a glass flask containing the seaweed Asparagopsis taxiformis on a beach, with waves crashing on the shore behind" src="https://images.theconversation.com/files/514617/original/file-20230310-440-eiamcv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/514617/original/file-20230310-440-eiamcv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/514617/original/file-20230310-440-eiamcv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/514617/original/file-20230310-440-eiamcv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/514617/original/file-20230310-440-eiamcv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/514617/original/file-20230310-440-eiamcv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/514617/original/file-20230310-440-eiamcv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Feeding cattle the red seaweed Asparagopsis taxiformis reduces their methane emissions.</span>
<span class="attribution"><a class="source" href="https://photos.aap.com.au/">Russell Freeman/AAP</a></span>
</figcaption>
</figure>
<p>Seaweed can improve intensive agriculture too. As highly effective <a href="https://www.sciencedirect.com/science/article/pii/S0960852423002560">biostimulants</a>, they provide viable alternatives to synthetic fertilisers. </p>
<p>Seaweed can also be used to recover and recycle excess nutrients such as nitrogen and phosphates from wastewater. So when you have large human populations, intensive land-based farming or aquaculture facilities releasing nutrients into our coastal systems, can be a very effective way to respond to that. Seaweed farms can do better when grown in areas with higher nutrient levels, such as <a href="https://www.tandfonline.com/doi/full/10.1080/13657300701202767">alongside fed finfish production facilities</a>.</p>
<p>Human health and medical benefits extend beyond commercially viable and tasty alternative protein sources. Some seaweeds can contain 10-30% protein, which is comparable with soy protein levels. But they also have the added natural advantage of relatively high levels of long-chain omega-3 fatty acids (brain food), which are <a href="https://link.springer.com/article/10.1007/s10311-022-01520-y">not naturally found in terrestrial food sources</a>.</p>
<p>Increasingly we are finding seaweeds with anticoagulant, anti-inflammatory, antioxidant, anticarcinogenic and antiviral properties. Several types of kelp have been shown to promote a <a href="https://www.sciencedirect.com/science/article/abs/pii/B9780123876690000028">beneficial</a> <a href="https://ift.onlinelibrary.wiley.com/doi/full/10.1111/1541-4337.12441">immune response</a>. </p>
<p>Seaweed supplements in animal feeds have also been shown to offer advantages such as improved gut health and digestive efficiency. This has the potential to <a href="https://www.tandfonline.com/doi/full/10.1080/01652176.2022.2061744">markedly improve yield</a> and other outcomes on farms.</p>
<h2>Let’s get on with it</h2>
<p>There are still challenges to overcome, and there may be more issues to contend with down the track. But if we support coordinated and appropriate research and development, focused on fast-tracking the benefits that seaweed has to offer, Australian seaweed really can play a big part in saving the world.</p>
<p>It’s worth mentioning here, several initiatives and funding bodies that are currently supporting seaweed research and development in Australia. Most notably the <a href="https://mbcrc.com/">Marine Bioproducts Co-operative Research Centre (MBCRC</a>), the <a href="https://blueeconomycrc.com.au/">Blue Economy CRC</a>, <a href="https://agrifutures.com.au/">AgriFutures Australia</a>, the <a href="https://www.frdc.com.au/">Fisheries Research and Development Corporation (FRDC</a>) and the <a href="https://www.seaweedalliance.org.au/">Australian Sustainable Seaweed Alliance (ASSA</a>). </p>
<p>And it’s really encouraging to see broader community engagement in this conversation including the panel discussion at the <a href="https://www.womadelaide.com.au/lineup">WOMADelaide Festival</a> <a href="https://www.womadelaide.com.au/lineup/the-planet-talks">Planet Talks</a> series. It’s great to have a chance to talk openly about the challenges while showcasing the opportunities. It’s complicated, but it’s exciting. Let’s get on with it.</p><img src="https://counter.theconversation.com/content/201459/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Catriona Macleod is a program leader in the Marine Bioproducts CRC (MBCRC) which actively supports research and development projects in the seaweed industry and is on the board of the Australian Sustainable Seaweed Alliance (ASSA). She has previously received funding from the Australian Co-operative Research Centres (CRC), Fisheries Research and Development Corporation (FRDC) and Agrifutures to support seaweed related research. She is affiliated with The Institute of Marine and Antarctic Studies at the University of Tasmania. </span></em></p>Seaweed is in the spotlight for so many reasons. It all sounds too good to be true. So can this wonder weed live up to expectations and fulfill its promise to save us from ourselves?Catriona Macleod, Professor, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1914952022-09-30T12:27:40Z2022-09-30T12:27:40ZWhat is a wetland? An ecologist explains<figure><img src="https://images.theconversation.com/files/487368/original/file-20220929-14-3kve60.jpg?ixlib=rb-1.1.0&rect=0%2C8%2C5375%2C3581&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A raccoon with a fish at the Corkscrew Swamp Sanctuary in Naples, Fla.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/naples-florida-corkscrew-swamp-sanctuary-racoon-procyon-news-photo/1395191565">Michael Siluk/UCG/Universal Images Group via Getty Images</a></span></figcaption></figure><p><a href="https://www.epa.gov/wetlands">Wetlands</a> are areas of land that are covered by water, or have flooded or waterlogged soils. They can have water on them either permanently or for just part of the year. </p>
<p>Whether it’s year-round or seasonal, this period of water saturation produces <a href="https://www.usgs.gov/news/science-snippet/wetland-word-hydric-soil">hydric soils</a>, which contain little or no oxygen. But this doesn’t mean that they are lifeless: Wetlands are full of unique water-loving plants and wildlife that have adapted to wet environments.</p>
<p>Wetlands can take many different forms, depending on the local climate, water conditions and land forms and features. For example, <a href="https://education.nationalgeographic.org/resource/swamp">swamps</a> are dominated by woody trees or shrubs. <a href="https://education.nationalgeographic.org/resource/marsh">Marshes</a> often have more grasslike plants, such as cattails and bulrushes. <a href="https://education.nationalgeographic.org/resource/bog">Bogs and fens</a> are areas that accumulate <a href="https://peatlands.org/peat/peat/">peat</a> – deposits of dead and partly decomposed plant materials that form organic-rich soil. </p>
<h2>Trillions of dollars in ecological benefits</h2>
<p>Wetlands are important environments for many reasons. They provide ecological services whose value has been estimated to be worth <a href="https://smartwatermagazine.com/news/ramsar/worth-wetlands-understanding-monetary-value-global-wetlands">more than US$47 trillion per year</a>. </p>
<p>For example, wetlands support very high levels of biodiversity. Scientists estimate that <a href="https://www.iucn.org/news/water/202001/call-ambitious-global-biodiversity-framework-world-wetlands-day-2020">40% of all species on Earth live or breed in wetlands</a>. </p>
<p>Wetlands are critical homes or stopovers for many species of migratory birds. In the central U.S. and Canada, for example, wetlands in the so-called <a href="https://www.ducks.org/conservation/where-ducks-unlimited-works/prairie-pothole-region">prairie pothole region</a> on the Great Plains support up to three-quarters of North America’s breeding ducks. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/GJETHYaVJvs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The hunting and conservation group Ducks Unlimited works to conserve prairie pothole wetlands on North America’s Great Plains.</span></figcaption>
</figure>
<p>Along with providing important habitat for everything from microbes to frogs to waterfowl, wetlands also work to improve water quality. They can capture surface runoff from cities and farmlands and work as <a href="https://www.ducks.ca/stories/science/wetlands-are-a-natural-remedy-for-canadas-sick-lakes/">natural water filters</a>, trapping excess nutrients that otherwise might create <a href="https://www.epa.gov/nutrientpollution/effects-dead-zones-and-harmful-algal-blooms">dead zones</a> in lakes and bays. Wetlands can also help remove other pollutants and trap suspended sediments that cloud water bodies, which <a href="https://www.chesapeakebay.net/news/blog/acreage-of-underwater-grasses-in-the-chesapeake-bay-decline-for-second-stra">can kill aquatic plants and animals</a>. </p>
<p>Because wetlands are often in low-lying areas of the landscape, they can store and slowly release surface water. Wetlands can be extremely important for reducing the <a href="https://www.iisd.org/articles/insight/wetlands-protecting-us-floods-and-saving-us-money">impacts of flooding</a>. In some places, water entering wetlands can also
recharge groundwater aquifers that are important for irrigation and drinking water.</p>
<p>Wetlands also act as important <a href="https://eos.org/editors-vox/managing-wetlands-to-improve-carbon-sequestration">carbon sinks</a>. As wetland plants grow, they remove carbon dioxide from the atmosphere. They they die, sink to the bottom of the wetland and decompose very slowly. </p>
<p>Over time, the carbon they contain accumulates in wetland soils, where it can be stored for hundreds of years. Conserving and restoring wetlands is an important strategy for regulating greenhouse gases and <a href="https://theconversation.com/what-the-world-needs-now-to-fight-climate-change-more-swamps-99198">mitigating the impacts of climate change</a>. </p>
<h2>Resources at risk</h2>
<p>Despite the many valuable services they provide, wetlands are constantly being destroyed by draining them or filling them in, mainly for farming and development. Since 1970, <a href="https://www.global-wetland-outlook.ramsar.org/">the planet has lost 35% of its wetlands</a>, a rate three times faster than the loss of forests. </p>
<p>Destruction and degradation of wetlands has led to the loss of many organisms that rely on wetland habitat, including birds, amphibians, fish, mammals and many insects. As one example, <a href="https://www.iucn.org/news/202112/dragonflies-threatened-wetlands-around-world-disappear-iucn-red-list">many dragonfly and damselfly species are declining worldwide</a> as the freshwater wetlands where they breed are drained and filled in. A marsh or bog may not look like a productive place, but wetlands teem with life and are critically important parts of our environment.</p><img src="https://counter.theconversation.com/content/191495/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jon Sweetman receives funding from the US EPA for work on wetland restoration. He is affiliated with the Society for Freshwater Science, the Ecological Society of America, and the Society of Wetland Scientists</span></em></p>The US Supreme Court opens its 2022-2023 term with a case that could greatly reduce federal protection for wetlands. Here is what makes these ecosystems valuable.Jon Sweetman, Assistant Research Professor of Ecosystem Science and Management, Penn StateLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1900312022-09-06T17:07:25Z2022-09-06T17:07:25ZCould Liz Truss allow new drilling for oil and gas and still strengthen the UK’s net zero target?<figure><img src="https://images.theconversation.com/files/483012/original/file-20220906-18-yxjddg.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4243%2C1755&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/offshore-oil-platform-north-sea-196784939">Donvictorio/Shutterstock</a></span></figcaption></figure><p>The UK’s new prime minister, Liz Truss, has pledged to <a href="https://www.cityam.com/exclusive-energy-boss-slams-liz-truss-plans-to-suspend-green-levies-as-nonsensical/">suspend green levies</a> on energy bills and look for “better ways to deliver our <a href="https://www.theweek.co.uk/news/politics/957484/what-liz-truss-and-rishi-sunak-are-saying-about-climate-change">net zero targets</a>”. Despite a <a href="https://theconversation.com/heatwave-britain-hits-40-3-c-heres-how-scientists-know-when-a-temperature-record-has-been-broken-187235">record-breaking</a> heatwave plus wildfires, droughts and floods worldwide, neither contender for the Conservative Party leadership felt the urge, as David Cameron once did, to <a href="https://www.theguardian.com/environment/blog/2016/apr/20/david-cameron-hug-a-husky-green-legacy-10-years">hug a husky</a> during the summer leadership campaign.</p>
<p>In her acceptance speech, Truss made clear her first priority is “dealing with people’s energy bills, but also dealing with the long-term issues we have on <a href="https://www.theguardian.com/politics/2022/sep/05/four-things-liz-truss-said-in-her-victory-speech-and-what-they-may-mean">energy supply</a>”. Many <a href="https://www.theguardian.com/commentisfree/2022/sep/04/liz-truss-petrolhead-politics-world-burns?CMP=Share_iOSApp_Other">read</a> this as a green light for licensing new oil and gas extraction and perhaps ending the moratorium on fracking. </p>
<p>But as a former foreign secretary, Truss must also know how <a href="https://www.theguardian.com/world/2022/sep/04/pakistan-floods-reparations-climate-disaster">flood victims in Pakistan</a> would react to Global Britain backtracking on its climate change commitments less than a year after cajoling the world into signing up to <a href="https://theconversation.com/five-things-you-need-to-know-about-the-glasgow-climate-pact-171799">the Glasgow Climate Pact</a>. </p>
<p>Can Truss preserve the UK’s reputation for climate leadership, and its target of net zero emissions of carbon dioxide (CO₂) by 2050, while appointing <a href="https://www.thenational.scot/news/20861555.jacob-rees-mogg-tipped-next-business-secretary-truss/">a business secretary</a> who wants to extract “<a href="https://www.standard.co.uk/news/uk/jacob-reesmogg-cabinet-north-sea-grant-shapps-prime-minister-b992366.html">every last drop</a>” of oil from the North Sea? As a physicist who <a href="https://theconversation.com/the-world-has-made-more-progress-on-climate-change-than-you-might-think-or-might-have-predicted-a-decade-ago-171787">helped identify</a> the need for net zero in the first place, I suspect the only way to do this would be to package these initiatives into an even bolder climate policy: make the UK the first country in the world to commit to <a href="https://www.researchgate.net/publication/358248129_Geological_Net_Zero_Geological_Carbon_Neutrality_-How_could_we_get_there">geological net zero</a>, linking future fossil fuel extraction and imports to permanent disposal of the CO₂ they generate. </p>
<h2>A target written in stone</h2>
<p>Achieving geological net zero <a href="https://www.nature.com/articles/s41558-021-01245-w">means</a> returning one tonne of CO₂ to storage in the Earth’s crust for every tonne generated by any continued burning of fossil fuels. It is a much more robust goal than net zero alone, because it leaves far less wriggle room for creative accounting of how much forests and other natural carbon sinks can soak up. And it is the bare minimum that a wealthy country and high historical emitter such as the UK should be committing to. </p>
<p>Crucially, the road to geological net zero need not be paved with subsidies. No taxpayer money is needed at all. What is needed is a licensing requirement on any firm extracting or importing fossil fuels into the UK to permanently dispose of a rising fraction of the CO₂ generated by the products they sell, either capturing it from their customers or drawing it out of the atmosphere, with that fraction rising to 100% by 2050. Since most of that carbon would probably be re-injected under the North Sea, lots of jobs would be created in north-east England, where the government has already <a href="https://www.theguardian.com/politics/2022/sep/04/revealed-levelling-up-fund-allocated-south-east-twice-as-much-as-north-east">promised investment</a>, paid for by companies like BP, whose boss recently <a href="https://www.mirror.co.uk/money/oil-giant-bp-more-cash-26176060">admitted</a> not knowing what to do with their excess profits.</p>
<p>The fossil fuel industry will insist that any such idea would make fossil fuels much, much more expensive – the last thing that is needed right now. But let’s think about that claim for a moment. Their most expensive option, capturing CO₂ from thin air to compensate for every single molecule generated by the products they sell, which they would only have to reach by 2050, would add less than 5p per kWh to the cost of supplying natural gas, and less than 60p to the cost of producing a litre of petrol. Technologies such as <a href="https://www.oxy.com/news/news-releases/1pointfive-and-carbon-engineering-announce-direct-air-capture-deployment-approach-to-enable-global-build-out-of-plants/">direct air capture</a> cost about <a href="https://www.goldmansachs.com/insights/pages/gs-research/carbonomics-innovation-deflation-and-affordable-de-carbonization/report.pdf">£200 to suck up a tonne of CO₂</a> today, and the industry would have 30 years to reduce the cost <a href="https://link.springer.com/article/10.1007/s11027-019-9847-y">further</a>.</p>
<p>That’s an additional cost of production, phased in gradually over three decades, that is less than their <a href="https://theconversation.com/what-the-invasion-of-ukraine-means-for-the-ipccs-latest-climate-change-report-180467">average increase in wholesale profits</a> since the beginning of 2022. Would these companies be able to pass it all on to consumers, on top of today’s prices? Or would competition from renewable energy mean they actually have to absorb some or all of this cost themselves? The only time the idea of a <a href="https://carbontakeback.org">carbon takeback obligation</a> came close to UK law, <a href="https://hansard.parliament.uk/Lords/2015-09-09/debates/15090934000410/EnergyBill(HL)">back in 2015</a>, it was bitterly opposed by the lobby group Oil and Gas UK, which suggests what they really think (I know, because a lobbyist in a nice suit took me out for a coffee and spent a good hour explaining to me what a terrible idea it was).</p>
<figure class="align-center ">
<img alt="Several blue barrels." src="https://images.theconversation.com/files/483015/original/file-20220906-14-oak4z6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/483015/original/file-20220906-14-oak4z6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/483015/original/file-20220906-14-oak4z6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/483015/original/file-20220906-14-oak4z6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/483015/original/file-20220906-14-oak4z6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/483015/original/file-20220906-14-oak4z6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/483015/original/file-20220906-14-oak4z6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Emissions from each new barrel of oil would need to be accounted for.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/metal-barrels-blue-color-182916398">Photomaster/Shutterstock</a></span>
</figcaption>
</figure>
<p>Knee-jerk opposition overcome, the next challenge would be standing up to fossil fuel companies offering to invest in wind farms instead of disposing of CO₂. Companies are welcome to invest in renewable energy if they want to, but those investments are no replacement for stopping the products they sell from causing global warming by keeping the CO₂ they generate out of the atmosphere. The alternative makes as much sense as a water company promoting its investment in water-absorbing peatlands as an excuse for dumping <a href="https://inews.co.uk/news/environment/sewage-beaches-holiday-england-water-companies-scandal-1803289">sewage on beaches</a>.</p>
<p>Countries are racing to diversify their fossil fuel supplies right now, and producers are begging for new extraction licenses. Banning all new extraction isn’t helpful if it simply increases our dependence in future on Russia and Saudi Arabia. But how can the UK license more oil and gas without locking in more emissions? The answer is simple: make the continued extraction or import of fossil fuels into the UK conditional on permanent CO₂ disposal, starting now and ramping up to 100% by 2050. And then challenge the country’s trading partners to do the same. </p>
<p>Require the world’s most profitable industry to get net zero done.</p><img src="https://counter.theconversation.com/content/190031/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Myles Allen is a member of the Advisory Board of Puro.Earth and receives research funding from UKRI and the European Commission.</span></em></p>Force oil and gas companies to dispose of a tonne of CO₂ for every one they emit.Myles Allen, Professor of Geosystem Science, Director of Oxford Net Zero, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1857262022-07-29T09:40:05Z2022-07-29T09:40:05ZClimate change: why we can’t rely on regrowing coastal habitats to offset carbon emissions<figure><img src="https://images.theconversation.com/files/476345/original/file-20220727-7627-p7o3a.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3168%2C2004&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/surabaya-indonesia-january-10-2013-small-2024667200">Akuditaputri/Shutterstock</a></span></figcaption></figure><p>Removing <a href="https://www.ipcc.ch/sr15/chapter/spm/">several hundred billion tonnes</a> of carbon from the atmosphere is now considered necessary to avert the worst effects of climate change. Using nature to help achieve that goal, by allowing habitats to regenerate, would seem to offer a <a href="https://www.science.org/doi/10.1126/science.abn9668">win-win solution</a> for the environment and the climate.</p>
<p>The sediments beneath mangrove forests, saltmarshes and seagrass meadows are <a href="https://www.grida.no/publications/145">rich in organic carbon</a> which has built up over many hundreds of years. Businesses and states keen to offset their emissions of greenhouse gases such as carbon dioxide (CO₂) are exploring ways to do so by funding the restoration of these so-called blue carbon habitats. </p>
<p>Many <a href="https://www.nature.com/articles/s43017-021-00224-1">academics</a> and <a href="https://www.mckinsey.com/business-functions/sustainability/our-insights/blue-carbon-the-potential-of-coastal-and-oceanic-climate-action">private sector groups</a> support the idea, assuming that the rate at which these ecosystems remove CO₂ from the atmosphere can be accurately predicted well into the future.</p>
<p>We are researchers who study how marine life, chemistry and the climate interact, and after examining the processes by which coastal habitats draw down (and release) planet-warming gases, we’re not convinced. Whether the climate benefits from restoring these habitats – by planting mangrove trees, for example – is far from certain, and there’s a real risk that the scale at which they can mitigate emissions has been massively oversold</p>
<p>Our <a href="https://www.frontiersin.org/articles/10.3389/fclim.2022.853666/full">new analysis</a> found several reasons why it is extremely difficult to work out a reliable figure for carbon accumulation by coastal ecosystems under current conditions. So we have a very shaky basis for calculating the future carbon offsets that restoration projects might provide over the next 50 to 100 years.</p>
<figure class="align-center ">
<img alt="Gloved hands handle a core of sediment surrounded by inundated vegetation." src="https://images.theconversation.com/files/475839/original/file-20220725-21-mo65cy.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/475839/original/file-20220725-21-mo65cy.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/475839/original/file-20220725-21-mo65cy.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/475839/original/file-20220725-21-mo65cy.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/475839/original/file-20220725-21-mo65cy.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/475839/original/file-20220725-21-mo65cy.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/475839/original/file-20220725-21-mo65cy.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A sediment core taken from a saltmarsh at high tide.</span>
<span class="attribution"><span class="source">Stephanie Nolte/University of East Anglia</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Causes of uncertainty</h2>
<p>Estimates of the rate at which blue carbon habitats remove CO₂ from the atmosphere vary widely. Across several hundred scientific studies, there was a 600-fold difference between the highest and lowest estimates for carbon burial in saltmarshes, a 76-fold difference for seagrasses and a 19-fold difference for mangroves. </p>
<p>Applying the average value from all these studies for a particular habitat is the easiest shortcut to estimate the carbon sequestration that can be expected from a new restoration project. But the variability means that the expected carbon offsetting could be badly wrong. And because there are many low values reported with just a few very high ones, there is a much greater chance of overestimating the climate benefit. </p>
<p>Differences in carbon removal rates exist even over distances of <a href="https://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lno.11607?casa_token=HB7n3gyVoFIAAAAA%3ArSG8Z_c3GTLxN_KenoXoICHwgLrPT9ELogBhmy_8YPoJlL9Bq39xbQ-Qcipz5CaaDnfrZcbOebxK5g4">just a few kilometers</a>. Many extra measurements are needed for credible carbon accounting, but these take time and effort, raising the cost of a restoration project. </p>
<p>Problems run deeper than that. The carbon burial rates reported in studies are usually determined indirectly, by sampling sediment at different depths to estimate its age. Burrowing organisms disturb and mix younger and older layers, causing errors in this dating process by making sediments seem younger, and carbon burial rates greater, than they really are.</p>
<figure class="align-center ">
<img alt="An aerial image of a coastal wetland with ponds and flowing water." src="https://images.theconversation.com/files/476349/original/file-20220727-1293-lpcchf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/476349/original/file-20220727-1293-lpcchf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/476349/original/file-20220727-1293-lpcchf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/476349/original/file-20220727-1293-lpcchf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/476349/original/file-20220727-1293-lpcchf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/476349/original/file-20220727-1293-lpcchf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/476349/original/file-20220727-1293-lpcchf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A coastal saltmarsh at Stiffkey, North Norfolk, UK.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/aerial-view-coastal-salt-marshes-stiffkey-1429758971">Dronegraphica/Shutterstock</a></span>
</figcaption>
</figure>
<p>Much of the carbon buried in coastal sediments comes from elsewhere, such as soil swept from the land and carried by rivers. The proportion of imported carbon can be as little as 10% or as much as 90%. Imported carbon should be excluded from estimates used in offset accounting to clarify how much was buried as a result of restoring the habitat and how much might have simply been buried regardless.</p>
<p>Unfortunately, imported carbon may be more resistant to decay. In a <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.14089">study</a> on one saltmarsh, the proportion of 50% imported carbon near the sediment surface increased to 80% in deeper layers. Since the deeper value represents the habitat’s long-term carbon burial rate, the direct contribution of a restored habitat to removing carbon may be much less important than thought. </p>
<p>Other processes which are difficult to quantify might increase rather than diminish the climate benefits of restoring blue carbon habitats. If plant debris from a coastal habitat is washed out to sea instead of accumulating in the sediment, it could still end up being stored for a long time <a href="https://royalsocietypublishing.org/doi/10.1098/rsbl.2018.0200">elsewhere</a>. It might sink to very deep water in the open ocean, for example. But scientists don’t know enough about the amounts of carbon typically involved in such processes to properly account for them.</p>
<p>Turning an oil palm plantation back into a mangrove forest or flooding a coastal area to make a saltmarsh should help the land accumulate carbon. But that same land could also <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020GB006858">release more</a> methane (otherwise known as marsh gas) and nitrous oxide – both powerful greenhouse gases – leaving no net climate benefit. </p>
<p>That’s because these gases are formed when there is insufficient oxygen in the soil or sediment, the same conditions that favour carbon accumulation. Technically demanding measurements are needed to find out exactly what is going on.</p>
<figure class="align-center ">
<img alt="Plastic tubes criss-cross tree saplings on a sandy shore." src="https://images.theconversation.com/files/475840/original/file-20220725-23-slro76.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/475840/original/file-20220725-23-slro76.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=283&fit=crop&dpr=1 600w, https://images.theconversation.com/files/475840/original/file-20220725-23-slro76.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=283&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/475840/original/file-20220725-23-slro76.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=283&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/475840/original/file-20220725-23-slro76.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=356&fit=crop&dpr=1 754w, https://images.theconversation.com/files/475840/original/file-20220725-23-slro76.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=356&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/475840/original/file-20220725-23-slro76.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=356&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Equipment measuring gas exchange in the sediment of an Australian mangrove swamp.</span>
<span class="attribution"><span class="source">Judith Rosentreter/Southern Cross University</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>And then there are calcifying animals and plants which grow in these habitats, particularly seagrass meadows. The strap-like leaves of seagrass are often covered by a white crust of shelled worms and coralline algae. When these organisms make their calcium carbonate covering, CO₂ is produced. </p>
<p>At an underwater meadow in Florida, <a href="https://www.science.org/doi/10.1126/sciadv.abj1372">more CO₂ was released than removed</a> by the seagrass itself. At other places, conditions may favour a chemical reaction between dissolved CO₂ and carbonate in the sediment, resulting in <a href="https://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lol2.10170">extra carbon uptake</a>. Again, sophisticated measurements are needed at each site to sort out the importance of these effects.</p>
<figure class="align-center ">
<img alt="A stand of underwater seagrass with white-flecked leaves." src="https://images.theconversation.com/files/475841/original/file-20220725-13-whzn7b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/475841/original/file-20220725-13-whzn7b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/475841/original/file-20220725-13-whzn7b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/475841/original/file-20220725-13-whzn7b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/475841/original/file-20220725-13-whzn7b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/475841/original/file-20220725-13-whzn7b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/475841/original/file-20220725-13-whzn7b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Mediterranean seagrass encrusted with coralline algae and worms with carbonate shells.</span>
<span class="attribution"><span class="source">David Luquet/CNRS & Sorbonne Universit</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Finally, there’s the future to consider. Will restored coastal ecosystems withstand the ravages of climate change, including heatwaves, storms and sea level rise? And will they be sufficiently well managed to protect against encroachment by agriculture, aquaculture, tourism and other industries and activities that may have caused the habitat to disappear in the first place? </p>
<p>Every effort should still be made to halt, and wherever possible reverse, the worldwide loss of coastal vegetation. Blue carbon habitats are, after all, more than carbon sinks – they also protect communities from <a href="https://theconversation.com/protecting-mangroves-can-prevent-billions-of-dollars-in-global-flooding-damage-every-year-132424">storms</a>, nurture biodiversity and species targeted by fisheries, and <a href="https://www.sciencedirect.com/science/article/abs/pii/S2212041622000195">improve water quality</a>.</p>
<p>We fervently hope that future protection of blue carbon habitats will be effective, and that global warming can be kept below the thresholds considered critical for their survival, <a href="https://www.ipcc.ch/srocc/chapter/chapter-5/">ranging from 2.3°C to 3.7°C</a> above pre-industrial levels. Unfortunately, that is far from certain. And if those temperature thresholds are exceeded, newly accumulated stores of carbon may be returned to the atmosphere when the vegetation is no longer there to prevent the sediment eroding. </p>
<p>Since the scale of long-term carbon removal and storage by blue carbon habitats is so uncertain, it is too risky to rely on as a means of offsetting continued emissions. The consequences of failing to deliver are too great. The priority must therefore be to double down on emission reductions, only using carbon removal methods to help achieve net zero where we are confident that they will work.</p><img src="https://counter.theconversation.com/content/185726/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Phil Williamson received funding from UKERC/NERC. Until 2020, he received a NERC salary as Science Coordinator for the UK Greenhouse Gas Removal programme. Its aims were to impartially assess the feasibility of different ways of removing CO₂ and other greenhouse gases from the atmosphere.</span></em></p><p class="fine-print"><em><span>Jean-Pierre Gattuso's has received funding from the Prince Albert II of Monaco Foundation, the Ocean Acidification International Coordination Centre of the International Atomic Energy Agency, the Veolia Foundation, the French Facility for Global Environment and the European Commission.</span></em></p>‘Blue carbon’ habitats can store a lot of carbon – but not reliably enough to offset emissions.Phil Williamson, Honorary Reader, University of East AngliaJean-Pierre Gattuso, Research Professor, CNRS, Iddri, Sorbonne UniversitéLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1830172022-05-26T15:04:00Z2022-05-26T15:04:00ZLarge trees are essential for healthy cities<figure><img src="https://images.theconversation.com/files/462899/original/file-20220512-22-pyh6gt.jpg?ixlib=rb-1.1.0&rect=7%2C0%2C986%2C663&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Although it is important to have a diversity of tree species in urban landscapes, planting and protecting taller species should be strongly encouraged.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Trees are important elements of our urban landscape. With <a href="https://data.worldbank.org/indicator/SP.URB.TOTL.IN.ZS">more than 50 per cent of the world’s population living in cities</a>, it is impossible to imagine cities without the many services and benefits trees provide to residents and ecosystems.</p>
<p>We saw evidence of this when COVID-19 measures were the most restrictive: urban park use <a href="https://ccpr.parkpeople.ca/2021/overview/lessons">increased dramatically</a>. This is no coincidence. The presence of trees promotes both physical and mental health, which is one of the main reasons city dwellers felt the need to <a href="https://www.fao.org/ecosystem-services-biodiversity/background/regulating-services/en/">spend time in green spaces</a>.</p>
<hr>
<p>
<em>
<strong>
À lire aussi :
<a href="https://theconversation.com/comment-prendre-soin-du-sol-et-de-la-terre-pour-favoriser-le-verdissement-en-ville-163873">Comment prendre soin du sol et de la terre pour favoriser le verdissement en ville</a>
</strong>
</em>
</p>
<hr>
<p>The trees we encounter every day on private property, on streets or in parks also contribute many environmental and climate regulation benefits, including the mitigation of city noise, capturing carbon and slowing water infiltration rates into soils.</p>
<p>Although a city’s total tree stock plays a role in the quality and quantity of ecosystem services, not all trees have the same characteristics or the same capacity to provide ecosystem services. So it is important to ask which trees are the most effective in delivering these benefits, why and what practices would promote such services?</p>
<p>We are part of the <a href="https://www.craum.ffgg.ulaval.ca">Research Chair on Urban Trees and their Environment</a> at Laval University, which aims to find solutions to help the long-term survival of trees in urban environments.</p>
<h2>Which trees provide the most benefits?</h2>
<p>In general, large trees have a better capacity to capture carbon from the air and store it, reduce atmospheric pollution and <a href="https://treecanada.ca/resources/canadian-urban-forest-compendium/17-stormwater-management-and-urban-forests/">prevent stormwater runoff</a>. </p>
<p>Trees with a larger trunk diameter have a greater woody biomass (amount of wood), which allows them to store more carbon than smaller trees. Similarly, trees’ ability to intercept precipitation and air pollutants increases with greater canopy size (the tops of dominant trees) and total leaf area (the total area of all leaves), which are both associated with greater overall tree size. As a result, larger trees are generally more effective than smaller ones at providing essential regulating services for urban environments and, especially, in a changing climate.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/454552/original/file-20220327-19-cmgjy.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="large tree in front of a house" src="https://images.theconversation.com/files/454552/original/file-20220327-19-cmgjy.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454552/original/file-20220327-19-cmgjy.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=607&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454552/original/file-20220327-19-cmgjy.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=607&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454552/original/file-20220327-19-cmgjy.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=607&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454552/original/file-20220327-19-cmgjy.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=763&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454552/original/file-20220327-19-cmgjy.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=763&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454552/original/file-20220327-19-cmgjy.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=763&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Large elm tree in a residential neighbourhood in Québec City. The planting and protection of large species should be strongly encouraged.</span>
<span class="attribution"><span class="source">(Alison Munson)</span>, <span class="license">Fourni par l'auteur</span></span>
</figcaption>
</figure>
<p>Planting large tree species also has significant economic benefits. One study reports that the annual net benefit of planting large tree species is <a href="https://www.brebookshop.com/samples/326911.pdf">44 per cent higher than that of a medium tree species and 92 per cent higher than that of a small tree species</a>. </p>
<p>The same study found it takes less than five years for the net benefits of these trees to outweigh the net costs. This can be explained in part by the fact that large trees increase real estate prices and land values, in addition to reducing energy costs for heating and cooling by regulating the microclimate.</p>
<p>However, the limited available overhead or underground space in urban areas means it is not always possible to plant large trees. In these conditions, smaller trees can also make an significant contribution.</p>
<p>Large trees play a critical role in the delivery of ecosystem services. But the ability to deliver these services is conditional on one thing: the trees must be in good condition. Those in poor condition have less capacity to deliver ecosystem services, since poor conditions impede growth, slow carbon sequestration and can also lead to <a href="https://hort.ifas.ufl.edu/woody/dead-branche-stop.shtml">canopy die-back</a>.</p>
<p>In urban settings, hostile environments can impede the growth and proper development of trees. Lack of space for the root system, soil compaction, limited soil moisture, <a href="https://www.bartlett.com/blog/2021/01/tree-advice/deicing-salts-and-trees-dont-mix">use of de-icing salts</a> and air pollution challenge the survival of young planted trees. In view of this, several management practices have been developed to encourage the growth and development of trees. Here are some examples:</p>
<ol>
<li><p>Plant the right tree in the right place. For example, some tree species are better adapted to certain climates or more tolerant than others to limited amounts of space. There are guides available for planting choices that are based on environmental characteristics, including soil conditions.</p></li>
<li><p>Avoid frequent pruning of large trees, which significantly reduces the leaf area and woody biomass of individual trees. One of the keys to reducing the need for pruning is to choose a tree species that is adapted to a given location.</p></li>
<li><p>Formally recognize the value of ecosystem services provided by large trees in order to introduce policies that support their conservation.</p></li>
</ol>
<h2>The importance of concrete actions</h2>
<p>Although large trees are generally more effective than small ones in providing certain ecosystem services, in the context of a changing climate, and where forest resilience is paramount, it is important not to put all our eggs in one basket and exclusively plant large tree species.</p>
<p>In fact, at the forest scale, some characteristics are positively correlated with the production of ecosystem services, including vertical heterogeneity (the amount of vegetation strata, ranging from flowering plants to dominant trees) and <a href="https://doi.org/10.1038/s41467-018-07082-4">shrub diversity</a>, which is the number of different species present.</p>
<p>Finally, the key things to remember are that large trees are extremely important, and that we benefit from efforts to preserve them. Moreover, planting large tree species should be encouraged, since there’s a tendency to plant small species in cities. Concrete actions can be taken right away to get the most out of urban trees now and over the long term. </p>
<p>It is up to us to make them happen!</p><img src="https://counter.theconversation.com/content/183017/count.gif" alt="La Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alison Munson is co-director of a research chair on urban forests and their environment, that is financed by the Ville de Québec. </span></em></p><p class="fine-print"><em><span>Anaïs Paré ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>There is a growing interest in planting small trees in urban areas. However, large trees have significant advantages.Alison Munson, Écologie forestière, écologie urbaine, sols urbains, Université LavalAnaïs Paré, Professionnelle de recherche pour la Chaire de recherche sur l'arbre urbain et son milieu (CRAUM), Université LavalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1761542022-02-13T18:48:09Z2022-02-13T18:48:09ZOceans are better at storing carbon than trees. In a warmer future, ocean carbon sinks could help stabilise our planet<figure><img src="https://images.theconversation.com/files/443911/original/file-20220201-23-hnijos.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">forams</span> </figcaption></figure><p>We think of trees and soil as carbon sinks, but the world’s oceans hold far larger carbon stocks and are more effective at storing carbon permanently.</p>
<p>In new <a href="https://doi.org/10.1029/2021PA004294">research</a> published today, we investigate the long-term rate of permanent carbon removal by seashells of plankton in the ocean near New Zealand. </p>
<p>We show that seashells have drawn down about the same amount of carbon as regional emissions of carbon dioxide, and this process was even higher during ancient periods of climate warming. </p>
<p>Humans are taking carbon out of the ground by burning fossil fuels deposited millions of years ago and putting it into the atmosphere as carbon dioxide.
The current rate of new fossil fuel formation is very low. Instead, the main geological (long-term) mechanism of carbon storage today is the formation of seashells that become preserved as sediment on the ocean floor. </p>
<p>The <a href="https://theconversation.com/expedition-reveals-the-violent-birth-of-earths-hidden-continent-zealandia-forged-in-a-ring-of-fire-130860">continent of Zealandia</a> is mostly submerged beneath the southwest Pacific Ocean but includes the islands of New Zealand and New Caledonia. </p>
<figure class="align-center ">
<img alt="A map of the Zealandia continent, southwest Pacific" src="https://images.theconversation.com/files/443914/original/file-20220201-13-q2tvkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/443914/original/file-20220201-13-q2tvkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=602&fit=crop&dpr=1 600w, https://images.theconversation.com/files/443914/original/file-20220201-13-q2tvkd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=602&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/443914/original/file-20220201-13-q2tvkd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=602&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/443914/original/file-20220201-13-q2tvkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=757&fit=crop&dpr=1 754w, https://images.theconversation.com/files/443914/original/file-20220201-13-q2tvkd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=757&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/443914/original/file-20220201-13-q2tvkd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=757&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The continent of Zealandia is about twice the size of India, but most of it lies more than 1000m deep in the southwest Pacific Ocean.</span>
<span class="attribution"><span class="source">Author provided</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><a href="https://www.globalcarbonproject.org/index.htm">Carbon dioxide emissions</a> from burning fossil fuels on the continent add up to about 45 million tonnes per year, which is 0.12% of the global total. </p>
<p>Our work documents a project that was part of the International Ocean Discovery Program (<a href="https://www.iodp.org/">IODP</a>). <a href="http://publications.iodp.org/proceedings/371/371title.html">Expedition 371</a> drilled into the seabed of Zealandia to investigate how the continent formed and to analyse ancient environmental changes recorded in its sediments. </p>
<h2>Drawing carbon to the ocean floor</h2>
<p>Organic carbon in the form of dead plants, algae and animals is mostly eaten by other creatures, mainly bacteria, in both the ocean and in forest soils. Most organisms in the ocean are so small (less than 1mm in size) they remain invisible, but as they die and sink, they transport carbon to the deep ocean. Their shells can accumulate on the seabed to make vast deposits of chalk and limestone. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/tiny-plankton-drive-processes-in-the-ocean-that-capture-twice-as-much-carbon-as-scientists-thought-136599">Tiny plankton drive processes in the ocean that capture twice as much carbon as scientists thought</a>
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</em>
</p>
<hr>
<p>The sediments we cored were many hundreds of metres thick and formed during warmer climates that might resemble the decades and centuries to come. We know the past environments from analysis of fossils. </p>
<p>Seashells, which are made of calcium carbonate, sequester significant amounts of carbon. The accumulation rate of shells averaged over the last million years was about 20 tonnes per square kilometre per year. </p>
<figure class="align-center ">
<img alt="Two researchers working on sediment cores." src="https://images.theconversation.com/files/443926/original/file-20220202-15-1dq0jmf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/443926/original/file-20220202-15-1dq0jmf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/443926/original/file-20220202-15-1dq0jmf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/443926/original/file-20220202-15-1dq0jmf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/443926/original/file-20220202-15-1dq0jmf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/443926/original/file-20220202-15-1dq0jmf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/443926/original/file-20220202-15-1dq0jmf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Researchers Xiaoli Zhou (US) and Yu-Hyeon Park (Republic of Korea) take samples of water from sediment cores during IODP Expedition 371.</span>
<span class="attribution"><span class="source">Laia Alegret, IODP</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>The total area of the Zealandia continent is about 6 million square kilometres, so the average rate of calcium carbonate storage was about 120 million tonnes per year, which is equivalent to 53 million tonnes of carbon dioxide per year. </p>
<p>This is about the same as emissions from burning fossil fuels on the continent today, within errors of calculation. However, a much larger area than just Zealandia is accumulating microscopic seashells. </p>
<figure class="align-center ">
<img alt="A map of ocean currents and regions of shell accumulation." src="https://images.theconversation.com/files/443924/original/file-20220202-19-5p69xd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/443924/original/file-20220202-19-5p69xd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=390&fit=crop&dpr=1 600w, https://images.theconversation.com/files/443924/original/file-20220202-19-5p69xd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=390&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/443924/original/file-20220202-19-5p69xd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=390&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/443924/original/file-20220202-19-5p69xd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=490&fit=crop&dpr=1 754w, https://images.theconversation.com/files/443924/original/file-20220202-19-5p69xd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=490&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/443924/original/file-20220202-19-5p69xd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=490&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">This map shows global ocean surface currents and regions of seabed (shaded) where calcium carbonate shells are accumulating.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1130/G36883.1">Rupert Sutherland</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>The planetary carbon cycle</h2>
<p>Earth naturally expels carbon dioxide from mineral springs and volcanoes, as rocks are cooked at depth. This is unlikely to be affected by climate change. The Earth stores carbon dioxide when rocks are altered at the surface and as seashells accumulate on the seabed. Both these mechanisms might be affected by climate change. </p>
<p>The biosphere and oceans also hold significant carbon stocks that are sure to change. It is a complex system and many scientists are trying to understand how it will respond to human activities. </p>
<p>Different parts of the carbon system will respond in different ways and at different rates. Our work provides clues as to what might happen in the ocean. </p>
<figure class="align-center ">
<img alt="This cartoon illustrates how carbon moves through the Earth system." src="https://images.theconversation.com/files/443925/original/file-20220202-13-vfw6pf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/443925/original/file-20220202-13-vfw6pf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=286&fit=crop&dpr=1 600w, https://images.theconversation.com/files/443925/original/file-20220202-13-vfw6pf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=286&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/443925/original/file-20220202-13-vfw6pf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=286&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/443925/original/file-20220202-13-vfw6pf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=359&fit=crop&dpr=1 754w, https://images.theconversation.com/files/443925/original/file-20220202-13-vfw6pf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=359&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/443925/original/file-20220202-13-vfw6pf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=359&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">This cartoon illustrates how carbon moves through the Earth system.</span>
<span class="attribution"><span class="source">Rupert Sutherland</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p>About 4-8 million years ago, the climate was warmer, carbon dioxide levels were similar or even higher than today, and the ocean was more acidic. However, we found the average accumulation rate of seashells on Zealandia was more than double that of the most recent million years. </p>
<p>This is a pattern seen elsewhere around the world. Warmer climates during this period had oceans that produced more seashells, but these data are average accumulation rates over million-year time scales. </p>
<p>The mechanism by which these ancient warmer oceans produced more seashells remains a subject of ongoing research (including ours). </p>
<p>Rivers and the wind deliver nutrients to the ocean, especially during extreme weather events, and changes can occur over short time scales. At the other extreme, fully integrated <a href="https://www.nature.com/articles/s41586-021-03884-7">climate models</a> show that large-scale reorganisation of ocean currents to enhance the supply of nutrients from deep waters could take centuries or even millennia. </p>
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Read more:
<a href="https://theconversation.com/the-ocean-is-essential-to-tackling-climate-change-so-why-has-it-been-neglected-in-global-climate-talks-171309">The ocean is essential to tackling climate change. So why has it been neglected in global climate talks?</a>
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<p>Our work highlights and quantifies the important role the ocean, and particularly the microscopic life within it, will eventually play in restoring balance to our planet. The rate at which dead plankton draw carbon to the deep ocean and small seashells permanently store it on the seabed is a significant proportion of human carbon dioxide emissions and it is likely to increase in the future. </p>
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<img alt="Palaeontologist Laia Alegret (Spain) and co-chief scientist Gerald Dickens (US) discuss a sediment core at the sampling table during IODP Expedition 371." src="https://images.theconversation.com/files/443927/original/file-20220202-27-jh7y3m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/443927/original/file-20220202-27-jh7y3m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/443927/original/file-20220202-27-jh7y3m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/443927/original/file-20220202-27-jh7y3m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/443927/original/file-20220202-27-jh7y3m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/443927/original/file-20220202-27-jh7y3m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/443927/original/file-20220202-27-jh7y3m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Palaeontologist Laia Alegret (Spain) and co-chief scientist Gerald Dickens (US) discuss a sediment core at the sampling table during IODP Expedition 371.</span>
<span class="attribution"><span class="source">Tim Fulton, IODP/JRSO</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p>Our work reveals that a warmer ocean may eventually produce more calcium carbonate shells than today’s ocean does, even though ocean acidification will almost certainly occur. </p>
<p>How quickly natural carbon sequestration in the ocean might change remains highly uncertain. It will take many centuries before we reach an ocean state similar to that found 4-8 million years ago. </p>
<p>More work is needed to understand how this transition might occur and whether it is possible and sensible to enhance biological productivity in our oceans to mitigate climate change and maintain or increase biodiversity.</p><img src="https://counter.theconversation.com/content/176154/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rupert Sutherland has received research funding from the New Zealand Government and IODP Expedition 371 was funded by a collaboration of international governments.</span></em></p><p class="fine-print"><em><span>Laia Alegret received funding from the Spanish Ministry of Science and Innovation and FEDER funds, project PID2019-105537RB-I00. </span></em></p>Tiny seashells draw carbon to the ocean floor when they die. This is the most significant geological process of carbon storage today, and it might increase in a warmer world, as it did in the past.Rupert Sutherland, Professor of tectonics and geophysics, Te Herenga Waka — Victoria University of WellingtonLaia Alegret, Professor in Paleontology, Universidad de ZaragozaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1691752021-10-13T11:57:00Z2021-10-13T11:57:00ZA global carbon removal industry is coming – experts explain the problems it must overcome<p>Each of its carbon-sucking units is the size of a shipping container, yet the world’s largest direct air capture machine – <a href="https://www.ft.com/content/8a942e30-0428-4567-8a6c-dc704ba3460a">the Orca plant in Iceland</a> – only captures and stores about 4,000 tonnes of CO₂ a year. That’s about <a href="https://www.businessinsider.com/carbon-capture-storage-expensive-climate-change-2021-9?r=US&IR=T">three seconds’ worth</a> of global emissions.</p>
<hr>
<iframe id="noa-web-audio-player" style="border: none" src="https://embed-player.newsoveraudio.com/v4?key=x84olp&id=https://theconversation.com/a-global-carbon-removal-industry-is-coming-experts-explain-the-problems-it-must-overcome-169175&bgColor=F5F5F5&color=D8352A&playColor=D8352A" width="100%" height="110px"></iframe>
<p><em>You can listen to more articles from The Conversation, narrated by Noa, <a href="https://theconversation.com/uk/topics/audio-narrated-99682">here</a>.</em> </p>
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<p>Still, the Intergovernmental Panel on Climate Change <a href="https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf">reports</a> that technologies that remove CO₂ from the air like this will be needed alongside deep cuts in emissions to reduce global warming. In fact, climate scientists modelling <a href="https://www.ipcc.ch/sr15/">pathways for stabilising warming at 1.5°C</a> (the goal of the Paris agreement) assume that a carbon removal industry based around one method may need to be around 40% the size of the current <a href="https://www.ipcc.ch/site/assets/uploads/sites/2/2019/02/SPM3b.png">fossil fuel industry</a>.</p>
<p>There are several ways to remove carbon from the atmosphere. One is called bioenergy with carbon capture and storage, or Beccs. Here, vast acres of fast-growing plants are grown and then harvested and burned to generate electricity or make biofuel for vehicles. Beccs can even use waste from farms or timber plantations. The carbon normally released during the burning or fermentation stage is instead captured and pumped underground in old oil and gas wells or deep rock formations called saline aquifers. These storage sites can be beneath land (which is common in the US) or the seabed. There are over 20 years of experience in storing CO₂ under the <a href="https://www.sciencedirect.com/science/article/pii/S1876610217317174">Norwegian North Sea</a>, for instance.</p>
<p>Attempts to calculate how much carbon removal is possible often address how much it will cost, or how much carbon can realistically be extracted from the atmosphere. This can be done by assessing the land area available to produce biomass crops, or the size of underground reservoirs for storing the gas.</p>
<p>But what scientists often overlook when predicting the future capacity of these technologies is how society will need to change to accommodate them. For instance, what will a sudden change to how land is used mean for communities and livelihoods? How can increasing demand for land to grow food or restore habitat be reconciled with the need to produce lots of biomass for Beccs? And who should even be able to make these decisions for them to be considered fair and ethical?</p>
<p>If world leaders at the UN climate summit in Glasgow fail to address these questions, they run the risk of making overly optimistic judgments about how much CO₂ it’s possible to remove. If it transpires that the international community cannot rely on these technologies as much as climate modelling suggests we need to, then society will need to decarbonise even faster to prevent catastrophic climate change.</p>
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Read more:
<a href="https://theconversation.com/climate-scientists-concept-of-net-zero-is-a-dangerous-trap-157368">Climate scientists: concept of net zero is a dangerous trap</a>
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<h2>Social and political issues matter</h2>
<p>There is only one demonstration <a href="https://www.sciencedirect.com/science/article/pii/S1876610217321215">Beccs project</a> operating in the world today, in Illinois, USA. Alongside other researchers, <a href="https://doi.org/10.1016/j.gloenvcha.2020.102073">we talked to experts</a> working in sectors like forestry and energy to understand what’s needed to bring this new industry to life. </p>
<p>These experts are aware of large-scale bioenergy projects, such as those cultivating sugar cane ethanol in Brazil, which have deprived local people of land and destroyed native habitat. Many of them worry that a global Beccs industry that developed from these practices would exacerbate inequality by, for example, reducing access to food and ultimately fail to remove carbon from the atmosphere by actually increasing deforestation. The UK’s largest power plant for generating energy from biomass, Drax, mostly imports wood chips from North America, while UK farmers grow grass for use in a handful of smaller-scale power plants. But as the UK develops a Beccs industry, rising demand for bioenergy could mean the cheapest and most exploitative sources win out.</p>
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<img alt="A road bisects a sugar cane crop with a refinery in the distance." src="https://images.theconversation.com/files/425923/original/file-20211012-17-1dji8cq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/425923/original/file-20211012-17-1dji8cq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/425923/original/file-20211012-17-1dji8cq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/425923/original/file-20211012-17-1dji8cq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/425923/original/file-20211012-17-1dji8cq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/425923/original/file-20211012-17-1dji8cq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/425923/original/file-20211012-17-1dji8cq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Sugar cane grown for ethanol production in Brazil.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sugar-cane-industry-627434789">Mailsonpignata/Shutterstock</a></span>
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<p>The experts were also unsure about whether there is even enough free land to accommodate expanding bioenergy crops. Many voiced concerns about the consequences for the rights of people living in and working on land that is earmarked for Beccs.</p>
<p>Some experts doubted there was sufficient political support – capable of transcending short-term electoral cycles – to pull off the necessary innovation to build carbon capture and storage capacity in the UK. This technology is needed not just for Beccs, but to decarbonise heavy industry, including steel manufacturing and chemicals.</p>
<p>We found that these social and political obstacles were rarely represented, if at all, in models of the global potential for carbon removal. Of course, some of these things can’t be modelled. Models aren’t usually designed to incorporate the nuances of decision-making at national, regional and local levels, or the importance of cultural and spiritual values that people endow landscapes. </p>
<p>World leaders need a more complete picture of the complexity we know exists in the real world before embarking on the construction of a global carbon removal industry. Making this happen is as much a question of who pays to remove the carbon and who has a say in how the land is managed, as details about technology. If the political and social limitations are not better understood, then it is hard to imagine how these carbon removal pipe dreams will get off the ground.</p>
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<img alt="COP26: the world's biggest climate talks" src="https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/424739/original/file-20211005-17-cgrf2z.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><strong>This story is part of The Conversation’s coverage on COP26, the Glasgow climate conference, by experts from around the world.</strong>
<br><em>Amid a rising tide of climate news and stories, The Conversation is here to clear the air and make sure you get information you can trust. <a href="https://page.theconversation.com/cop26-glasgow-2021-climate-change-summit/"><strong>More.</strong></a></em> </p>
<hr><img src="https://counter.theconversation.com/content/169175/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Johanna Forster receives funding from Natural Environment Research Council (NERC)</span></em></p><p class="fine-print"><em><span>Naomi Vaughan receives funding from Natural Environment Research Council (NERC). </span></em></p>Removing carbon from the atmosphere is as much a social problem as a technical one.Johanna Forster, Lecturer in Environment and International Development, University of East AngliaNaomi Vaughan, Senior Lecturer in Climate Change, University of East AngliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1689182021-09-30T14:01:04Z2021-09-30T14:01:04ZCanada’s federal election made big strides for climate and the environment<figure><img src="https://images.theconversation.com/files/423928/original/file-20210929-66155-x1rxb8.jpg?ixlib=rb-1.1.0&rect=80%2C89%2C5910%2C3898&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Prime Minister Justin Trudeau is seeing nothing but blue skies ahead when it comes to his policies on climate change. But will the newly re-elected Liberal government follow through?</span> <span class="attribution"><span class="source">THE CANADIAN PRESS/Sean Kilpatrick </span></span></figcaption></figure><iframe style="width: 100%; height: 175px; border: none; position: relative; z-index: 1;" allowtransparency="" src="https://narrations.ad-auris.com/widget/the-conversation-canada/canada’s-federal-election-made-big-strides-for-climate-and-the-environment" width="100%" height="400"></iframe>
<p>The outcome of the recent federal election — a Liberal minority dependent on the NDP or Bloc Québécois for support — has been widely seen as having a “Groundhog Day” aspect to it. It left the composition of Parliament very much as it was before, <a href="https://www.cbc.ca/news/politics/federal-election-call-1.6141189">reinforcing questions about the necessity</a> of the election in the first place.</p>
<p>Yet the election has major implications for Canada’s approach to climate change and other environmental issues. Many progressives likely wanted the result: a Liberal government — but one they may not entirely trust to meet its promises on climate, child care and a host of other issues — reliant on more progressive parties to stay in office. </p>
<p>The overall outcome may have actually left Canada better positioned than before the election to make significant progress on reducing its greenhouse gas emissions.</p>
<h2>Holding the progressive vote</h2>
<p>The Liberals’ efforts to hold onto progressive voters in the face of challenges from the NDP, Greens and, in Québec, the Bloc Québécois, translated into an impressive menu of climate commitments. </p>
<p>Even before the election, the government expanded <a href="https://www.canada.ca/en/environment-climate-change/news/2021/04/canadas-enhanced-nationally-determined-contribution.html">Canada’s commitment to lower greenhouse gases</a> to a 40 to 45 per cent reduction by 2030 relative to 2005. (Canada’s previous target had been 30 per cent below 2005 levels.) </p>
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Read more:
<a href="https://theconversation.com/canada-finally-has-a-climate-plan-that-will-let-it-meet-its-carbon-targets-by-2030-152133">Canada finally has a climate plan that will let it meet its carbon targets by 2030</a>
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<p>Canada has also said it will <a href="https://www.canada.ca/en/services/environment/weather/climatechange/climate-plan/net-zero-emissions-2050.html">reach net-zero emissions by 2050</a>. Under that scenario, the details of which have yet to be <a href="https://www.theenergymix.com/2021/07/20/exclusive-experts-press-trudeau-to-link-energy-planning-to-1-5c-targets/">fully developed or modelled</a>, any remaining greenhouse gas emissions would have to be balanced by the amounts absorbed by biological processes (such as growing trees) and carbon sequestration or storage technologies.</p>
<p>The government’s December 2020 <a href="https://www.canada.ca/en/services/environment/weather/climatechange/climate-plan/climate-plan-overview/healthy-environment-healthy-economy.html">climate policy paper</a> proposed to increase the backstop federal carbon price to $170 per tonne by 2030. It is now expected to follow through on that.</p>
<p>The campaign produced <a href="https://liberal.ca/our-platform/cap-and-cut-emissions-from-oil-and-gas/">a promise to ensure the oil and gas sector</a> hits net-zero emissions by 2050, “with five-year targets starting in 2025.” There were also commitments to a <a href="https://liberal.ca/our-platform/cutting-methane-emissions/">75 per cent</a> reduction in fossil industry methane emissions from 2012 levels by 2030, and to “develop a plan to <a href="https://liberal.ca/our-platform/eliminating-subsidies-and-public-financing-for-fossil-fuel/">phase-out</a> public financing of the fossil fuel sector, including from Crown corporations.”</p>
<h2>Electricity, transportation and buildings</h2>
<p>About 17 per cent of Canada’s electricity comes from fossil fuels. In addition to the planned phase-out of conventional coal-fired electricity generation by 2030, a proposed “<a href="https://liberal.ca/our-platform/our-clean-power-advantage/">clean electricity standard</a>” would bring the electricity grid to net-zero by 2035. <a href="https://liberal.ca/our-platform/eliminating-thermal-coal-exports/">Thermal coal</a> exports would end by 2030.</p>
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<a href="https://images.theconversation.com/files/423861/original/file-20210929-13-pxdwwy.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Graphic showing how hydropower, nuclear, gas, coal, wind, solar, oil and other renewables contribute to electricity production in Canada." src="https://images.theconversation.com/files/423861/original/file-20210929-13-pxdwwy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/423861/original/file-20210929-13-pxdwwy.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/423861/original/file-20210929-13-pxdwwy.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/423861/original/file-20210929-13-pxdwwy.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/423861/original/file-20210929-13-pxdwwy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=532&fit=crop&dpr=1 754w, https://images.theconversation.com/files/423861/original/file-20210929-13-pxdwwy.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=532&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/423861/original/file-20210929-13-pxdwwy.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=532&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The burning of fossil fuels — coal, oil and gas — to produce electricity is a major source of greenhouse gases around the world. While Canada’s dependence on coal and oil for electricity has declined in the past 20 years, gas has been on the rise.</span>
<span class="attribution"><a class="source" href="https://ourworldindata.org/grapher/share-elec-by-source?country=~CAN">(OurWorldInData.org)</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>Transportation is the <a href="https://www.canada.ca/en/environment-climate-change/services/environmental-indicators/greenhouse-gas-emissions.html">second-largest source of greenhouse gas emissions in Canada</a>. The federal government has <a href="https://liberal.ca/climate/100-zero-emissions-car-sales-by-2035/">accelerated its target</a> so that every new passenger vehicle sold in 2035 and beyond is a zero-emission vehicle (ZEV). The commitments come with electric vehicle rebates of up to $5,000 for 500,000 buyers, plus 50,000 new charging stations across the country. And a low-carbon fuel standard would reduce emissions from gas-burning vehicles that remain on the road.</p>
<p>For homes and buildings, which account for about 13 per cent of Canada’s emissions, the government has <a href="https://liberal.ca/climate/a-retrofit-economy-that-cuts-pollution-and-creates-jobs/">promised $5,000 energy retrofit grants for nearly half a million households</a>, with interest-free loans of up to $40,000 for deeper retrofits. There will also be a national strategy to bring the building stock to net-zero by 2050 with “ambitious milestones along the way.”</p>
<h2>Following through will be crucial</h2>
<p>The crucial question now will be the follow-though on these commitments. Many of the government’s promises, like the commitments to reduce fossil fuel and electricity sector emissions, could lead to significant federal-provincial conflicts, particularly with Alberta and Saskatchewan. </p>
<p>Over the past six years, the Liberals’ approach to addressing climate change has had some profound contradictions. The government purchased and approved the <a href="https://theconversation.com/canadas-liberals-make-it-hard-for-green-voters-to-love-them-122935">Trans Mountain pipeline</a>, and it has supported controversial technologies like <a href="https://policyoptions.irpp.org/magazines/november-2020/canadas-newest-nuclear-industry-dream-is-a-potential-nightmare/">small modular nuclear reactors</a>, <a href="https://www.ciel.org/wp-content/uploads/2021/07/CCS-Letter_FINAL_CAN-1.pdf">carbon capture and storage</a>, and fossil-fuel dependent “blue” and “grey” <a href="https://www.pembina.org/pub/hydrogen-primer">hydrogen</a>.</p>
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Read more:
<a href="https://theconversation.com/why-green-hydrogen-but-not-grey-could-help-solve-climate-change-162987">Why green hydrogen — but not grey — could help solve climate change</a>
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<p>To its credit, Prime Minister Justin Trudeau’s government had already implemented far more substantive climate policies than all of its predecessors, Liberal and Conservative, combined. The government’s minority status, dependent on two opposition parties with strong commitments to climate action, will help see these further commitments through to implementation, even if some say its <a href="https://ipolitics.ca/2021/08/21/liberal-and-conservative-climate-promises-fall-short-experts-say/">pledges still fall short of what is needed to meet the revised emissions reduction targets</a>.</p>
<p>The election also had significant implications for the other parties. The credibility of the Conservative party’s stance on climate change remains suspect, and is reinforced by the <a href="https://sei.info.yorku.ca/files/2012/12/TheEnvironment.pdf?x60126">anti-environment legacy</a> of the Stephen Harper government and the behaviour of current Conservative provincial governments <a href="https://www.nationalobserver.com/2019/09/13/opinion/global-assault-environmental-rights-behind-jason-kenneys-war">in Alberta</a>, <a href="https://leaderpost.com/opinion/columnists/moe-ducking-talk-of-global-warming-ghg-reduction-for-political-gain">Saskatchewan</a> <a href="https://theconversation.com/new-and-improved-doug-ford-doesnt-extend-to-the-environment-128432">and Ontario</a>. <a href="https://globalnews.ca/news/8200829/future-of-canadas-greens-in-the-spotlight-after-election-setbacks/">Support for the Green Party collapsed</a> to its lowest level in two decades, yet the <a href="https://www.thestar.com/politics/federal/2021/09/20/ndp-tempers-expectations-as-early-results-put-party-far-behind-rivals.html">NDP failed to make any significant gains</a> among progressive voters despite a relatively strong campaign performance by Jagmeet Singh. </p>
<p>The overall results have left Canada reasonably well-positioned to move forward on its climate commitments. The question now will be whether the re-elected Trudeau government will carry through on its promises. Its survival through the next federal election may well depend on the results.</p><img src="https://counter.theconversation.com/content/168918/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Winfield receives funding from the Social Sciences and Humanities Research Council of Canada</span></em></p>While the outcome of the 2021 federal election offered little in the way of change, it may have left Canada better positioned to make progress on reducing greenhouse gas emissions.Mark Winfield, Professor of Environmental Studies, York University, CanadaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1602432021-06-30T12:12:33Z2021-06-30T12:12:33ZTo make agriculture more climate-friendly, carbon farming needs clear rules<figure><img src="https://images.theconversation.com/files/408481/original/file-20210626-17-3d0f70.jpg?ixlib=rb-1.1.0&rect=0%2C4%2C2828%2C1881&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Soybeans sprout on an Illinois farm through corn stubble left on an unplowed field from the previous season – an example of no-till farming.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/dgETmg">Paige Buck, USDA/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>As the effects of <a href="https://climate.nasa.gov/effects/">climate change</a> intensify and <a href="https://doi.org/10.1002/wcc.621">paths for limiting global warming narrow</a>, politicians, media and environmental advocates have rallied behind “carbon farming” as a mutually beneficial strategy for society, the environment and farmers.</p>
<p>Agriculture covers <a href="https://ourworldindata.org/environmental-impacts-of-food">more than half of Earth’s terrestrial surface</a> and contributes <a href="https://www.ipcc.ch/srccl/chapter/chapter-5/">roughly one-third</a> of global greenhouse gas emissions. Paying farmers to restore <a href="https://doi.org/10.1073/pnas.1706103114">carbon-depleted</a> soils offers a tantalizing opportunity for <a href="https://doi.org/10.1038/s41893-020-0491-z">a natural climate solution</a> that could help nations to meet their commitments under the international <a href="https://unfccc.int/process-and-meetings/the-paris-agreement/the-paris-agreement">Paris climate agreement</a> to stabilize global warming below 2 degrees Celsius. </p>
<p>An international initiative called “<a href="https://www.4p1000.org">4 per 1000</a>,” launched at the <a href="https://www.cop21paris.org/about/cop21">2015 Paris climate conference</a>, showed that increasing soil carbon worldwide by just 0.4% yearly could <a href="https://doi.org/10.1016/j.still.2017.12.002">offset that year’s new growth in carbon dioxide emissions from fossil fuel emissions</a>. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/408943/original/file-20210629-24-1lvhasn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Pig sunbathing in pasture." src="https://images.theconversation.com/files/408943/original/file-20210629-24-1lvhasn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/408943/original/file-20210629-24-1lvhasn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=491&fit=crop&dpr=1 600w, https://images.theconversation.com/files/408943/original/file-20210629-24-1lvhasn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=491&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/408943/original/file-20210629-24-1lvhasn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=491&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/408943/original/file-20210629-24-1lvhasn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=617&fit=crop&dpr=1 754w, https://images.theconversation.com/files/408943/original/file-20210629-24-1lvhasn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=617&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/408943/original/file-20210629-24-1lvhasn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=617&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A free-range pig at the Stone Brns Center for Food and Agriculture in New York. Raising livestock and crops together can boost soil carbon through the animals’ grazing patterns and natural manure distribution.</span>
<span class="attribution"><span class="source">Francesca Cotrufo</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Research shows that farmers and <a href="https://doi.org/10.1038/ncomms7995">ranchers</a> can also make their operations <a href="https://doi.org/10.1088/1748-9326/abe492">more resilient</a> to <a href="https://doi.org/10.1016/j.agsy.2021.103085">increasingly variable weather</a> by adopting practices that promote soil carbon sequestration. This prospect led us to <a href="https://www.research.colostate.edu/cip/scsc/">establish a center</a> at Colorado State University that develops and implements <a href="https://scholar.google.com/citations?user=i4i0ZvoAAAAJ&hl=en">soil-based</a> <a href="https://scholar.google.com/citations?user=HRySep8AAAAJ&hl=en">solutions</a> to <a href="https://scholar.google.com/citations?user=Jg8EQ28AAAAJ&hl=en">climate</a> <a href="https://scholar.google.com/citations?user=Prw0xGgAAAAJ&hl=en">change</a>. </p>
<p>While many policy options exist to <a href="https://www.oecd-ilibrary.org/sites/16af156c-en/index.html?itemId=/content/component/16af156c-en">reduce emissions from agricuture</a>, carbon farming has sparked <a href="https://www.politico.com/news/2021/06/24/senate-farmers-carbon-agriculture-496029">bipartisan U.S. legislation</a> and attracted <a href="https://www.greenbiz.com/article/how-carbon-smart-farming-catalyzing-big-bucks-needed-transform-way-america-eats">investors’ attention</a>. Critics <a href="https://www.wri.org/insights/insider-further-explanation-potential-contribution-soil-carbon-sequestration-working">question</a> its true potential, however. Some environment and justice advocacy groups argue that paying farmers <a href="https://modernfarmer.com/2021/04/environmental-groups-call-bidens-carbon-bank-plan-a-scam/">won’t do much to increase soil carbon</a>, and could allow polluting industries such as manufacturing to avoid necessary emission reductions by buying soil carbon credits from farmers instead.</p>
<p>Given the momentum behind carbon farming as a climate change mitigation strategy, we believe now is the time to establish clear standards that ensure that only real net changes in carbon receive financial rewards.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/AY9YVwJZDvw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Increasing carbon storage in soil can help stabilize the climate and support food production.</span></figcaption>
</figure>
<h2>Carbon farming basics</h2>
<p>As plants grow, they pull carbon from the atmosphere, and soil soaks it up and stores it. The amount of carbon stored <a href="https://doi.org/10.1016/j.still.2013.10.002">varies significantly</a> across soil type and climate. </p>
<p>Traditional farming methods that sequester carbon <a href="https://doi.org/10.1016/0167-8809(92)90095-S">have existed for millennia</a>. For example, minimizing soil disturbance through <a href="https://doi.org/10.2136/sssaj2013.09.0422">no-till farming</a> reduces carbon loss to the atmosphere. <a href="https://doi.org/10.3389/fsufs.2021.564900">Diversifying crops</a> and planting <a href="https://doi.org/10.1007/s13593-011-0056-7">legumes</a>, <a href="https://doi.org/10.1093/biosci/biy014">perennials</a> and <a href="https://esajournals.onlinelibrary.wiley.com/doi/10.1002/eap.2278">cover crops</a> returns more carbon to the soil, and sustains soil microbes that <a href="https://theconversation.com/to-restore-our-soils-feed-the-microbes-79616">play key roles in carbon storage</a>. </p>
<p>Another climate-friendly strategy is raising livestock and crops together. Rotating cows among pastures allows grasses to recover from grazing, and the animals’ manure and the impacts of their grazing <a href="https://doi.org/10.1016/j.jenvman.2021.112409">regenerate carbon in soils</a>. </p>
<p>Some farmers use these practices, which often are called “<a href="https://theconversation.com/regenerative-agriculture-can-make-farmers-stewards-of-the-land-again-110570">regenerative agriculture</a>,” particularly in <a href="https://www.chelseagreen.com/product/farming-while-black/">Black</a> and <a href="https://www.nativefoodsystems.org/">Indigenous communities</a> that have been <a href="https://flexpub.com/preview/dispossession">excluded from access to capital and government subsidies</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/408941/original/file-20210629-16-1okuhx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Cross section of prairie soil with deep roots." src="https://images.theconversation.com/files/408941/original/file-20210629-16-1okuhx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/408941/original/file-20210629-16-1okuhx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/408941/original/file-20210629-16-1okuhx3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/408941/original/file-20210629-16-1okuhx3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/408941/original/file-20210629-16-1okuhx3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/408941/original/file-20210629-16-1okuhx3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/408941/original/file-20210629-16-1okuhx3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The deep roots of Kernza, a perennial grain, reduce erosion, help the plant tolerate drought and add soil carbon deeper in the ground than shorter-rooted annual grains. Kernza, the first commercially viable perennial grain in the U.S., was developed by The Land Institute, based in Salina, Kansas.</span>
<span class="attribution"><span class="source">Francesca Cotrufo</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Soil: A low-cost solution</h2>
<p>Increasing soil carbon through techniques like no-till is relatively inexpensive. Studies estimate that carbon farming costs <a href="https://doi.org/10.1038/s41893-020-0491-z">US$10-$100 per ton of CO2 removed</a>, compared with $100-$1,000 per ton for technologies that <a href="https://www.iea.org/reports/direct-air-capture">mechanically remove carbon from the air</a>.</p>
<p>Carbon farming is also a potential revenue stream for farmers and ranchers, who can <a href="https://www.wisfarmer.com/story/news/2021/04/18/what-farmers-should-know-selling-carbon-credits/7280044002/">sell the credits they earn in carbon markets</a>. Large-scale greenhouse gas emitters, such as manufacturers, purchase these credits to offset their own emissions.</p>
<p>Companies such as <a href="https://www.indigoag.com/pages/news/first-companies-commit-to-purchasing-verified-agricultural-carbon-credits">IndigoAg</a> and <a href="https://locusag.com/shopify-will-be-first-high-volume-corporate-buyer-of-carbon-credits-from-a-us-carbonnow-farmer/">Nori</a> are already facilitating payments to farmers for carbon credits. And on June 24, 2021, the U.S. Senate passed the <a href="https://www.congress.gov/bill/117th-congress/senate-bill/1251/cosponsors?r=46&s=1&searchResultViewType=expanded">Growing Climate Solutions Act of 2021</a> by a vote of 92-8. The bill would authorize the U.S. Department of Agriculture to help farmers, ranchers and private forest landowners participate in carbon markets.</p>
<p>So far, however, there are no universal standards for measuring, reporting or verifying agricultural carbon credits. Here are the questions we see as top priorities.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1352640593151758336"}"></div></p>
<h2>Assessing carbon storage</h2>
<p>One major challenge is that soils absorb varying amounts of carbon depending on depth, texture and mineral content. While <a href="https://doi.org/10.3389/fclim.2019.00008">certain practices increase carbon storage</a>, quantifying how much is stored and for how long is critical for assigning dollar values to them. The <a href="https://doi.org/10.1111/gcb.15613">markets and practices</a> that work in different locations also vary widely.</p>
<p>Some scientific models offer <a href="https://doi.org/10.3389/fsufs.2021.564900">estimates of carbon sequestration for various climates and soil types</a> based on averages over large areas. We believe that regulators need <a href="https://doi.org/10.5194/bg-18-3147-2021">rigorous models</a> verified by measurements to avoid crediting carbon that never ends up in soil or doesn’t remain there for long. </p>
<p>But verification isn’t easy. Scientists are still searching for <a href="https://doi.org/10.1111/gcb.14815">quick, accurate, cost-effective ways</a> to sample and analyze soils. </p>
<p>Possible approaches include <a href="https://doi.org/10.3389/fenvs.2021.634472">infrared spectroscopy</a> – which identifies materials in soil by analyzing how they absorb or reflect infrared light – or <a href="https://doi.org/10.1038/s41561-021-00744-x">machine learning</a>, which can find patterns in large data sets quickly. Studies conducted in the <a href="https://link.springer.com/article/10.1007%2Fs10533-021-00755-1">U.S. Great Plains</a>, <a href="https://doi.org/10.3389/fenvs.2021.634472">the United Kingdom and the European Union</a> suggest these are promising, low-cost methods. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/408483/original/file-20210626-14-im52kz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Graphic showing roadblocks to soil carbon market integration." src="https://images.theconversation.com/files/408483/original/file-20210626-14-im52kz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/408483/original/file-20210626-14-im52kz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=419&fit=crop&dpr=1 600w, https://images.theconversation.com/files/408483/original/file-20210626-14-im52kz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=419&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/408483/original/file-20210626-14-im52kz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=419&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/408483/original/file-20210626-14-im52kz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=526&fit=crop&dpr=1 754w, https://images.theconversation.com/files/408483/original/file-20210626-14-im52kz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=526&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/408483/original/file-20210626-14-im52kz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=526&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Integrating carbon into markets poses scientific, economic and technical challenges.</span>
<span class="attribution"><a class="source" href="https://www.research.colostate.edu/cip/scsc/">CSU Soil Carbon Solutions Center</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Another priority is developing national minimum standards to predict and properly value soil carbon capture. Carbon may reside in soil anywhere from days to millennia, so time scale is an important consideration for markets. In our view, credits should reflect the duration carbon resides in soil, with full offsets generated only for <a href="https://theconversation.com/soil-carbon-is-a-valuable-resource-but-all-soil-carbon-is-not-created-equal-129175">longer-lasting storage</a>.</p>
<p>We also believe that these programs must consider an operation’s net greenhouse gas emissions. For example, practices may store more carbon in soil but also increase emissions of <a href="https://doi.org/10.1111/gcb.15342">nitrous oxide, another greenhouse gas</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/408530/original/file-20210627-24-1gkfh46.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Well-designed soil carbon policies will benefit farmers and society." src="https://images.theconversation.com/files/408530/original/file-20210627-24-1gkfh46.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/408530/original/file-20210627-24-1gkfh46.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=522&fit=crop&dpr=1 600w, https://images.theconversation.com/files/408530/original/file-20210627-24-1gkfh46.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=522&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/408530/original/file-20210627-24-1gkfh46.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=522&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/408530/original/file-20210627-24-1gkfh46.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=656&fit=crop&dpr=1 754w, https://images.theconversation.com/files/408530/original/file-20210627-24-1gkfh46.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=656&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/408530/original/file-20210627-24-1gkfh46.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=656&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Backed by effective technologies and policies, carbon farming can improve ecosystems and help to slow climate change.</span>
<span class="attribution"><a class="source" href="https://www.research.colostate.edu/cip/scsc/">CSU Soil Carbon Solutions Center</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Benefits and challenges</h2>
<p>Rebuilding carbon-rich soil supports farmers’ bottom lines by improving soil health and <a href="https://doi.org/10.5194/soil-5-15-2019">increasing crop yields</a>. But federal incentives could preferentially provide resources to <a href="https://www.ers.usda.gov/amber-waves/2017/december/us-cropland-is-consolidating-into-larger-farms/">big operations</a> that have greater ability to sequester carbon on their vast acreage. </p>
<p>That’s been the case with U.S. farm subsidies: Over the past 25 years, <a href="https://farm.ewg.org/progdetail.php?fips=00000&progcode=totalfarm&page=conc&regionname=theUnitedStates">10% of the largest farms received 78% of subsidies</a>. </p>
<p>Since these practices benefit farmers, some may use them even without policy incentives. As we see it, <a href="https://www.offsetguide.org/high-quality-offsets/additionality">to avoid paying for soil carbon increases that would have occurred anyway</a>, carbon banks should avoid crediting farms for adopting practices known to be profitable in their regions. </p>
<p>Ultimately, the goals of climate policy include curbing greenhouse gas emissions and actively removing carbon dioxide from the atmosphere. Before farmers receive soil carbon credits they can sell to offset other sources of emissions, we believe their value must be accurately assessed to ensure that society gets what it pays for.</p>
<p><em>Editor’s note: This article has been updated to reflect that IndigoAg does not purchase carbon credits.</em></p>
<p>[<em>Get the best of The Conversation, every weekend.</em> <a href="https://theconversation.com/us/newsletters/weekly-highlights-61?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=weeklybest">Sign up for our weekly newsletter</a>.]</p><img src="https://counter.theconversation.com/content/160243/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Laura van der Pol receives funding from the United Stated Department of Agriculture National Institute of Food and Agriculture as well as the National Science Foundation Graduate Research Fellowship Program.</span></em></p><p class="fine-print"><em><span>Dale Manning receives funding from USDA.</span></em></p><p class="fine-print"><em><span>Francesca Cotrufo receives funding from
NSF, USDA, DOE, Shell, MacDonald, GeneralMills
She is a founding member of Cquester Analytics LLC</span></em></p><p class="fine-print"><em><span>Megan Machmuller receives funding from WSARE, CDA, USDA. She is a founding member of Cquester Analytics LLC.</span></em></p>Policymakers want to pay farmers for storing carbon in soil, but there are no uniform rules yet for measuring, reporting or verifying the results. Four scholars offer some ground rules.Laura van der Pol, Ph.D Student in Ecology, Colorado State UniversityDale Manning, Associate Professor of Agricultural and Resource Economics, Colorado State UniversityFrancesca Cotrufo, Professor, Department of Soil and Crop Sciences, Colorado State UniversityMegan Machmuller, Research Scientist, Colorado State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1613582021-06-24T20:12:17Z2021-06-24T20:12:17ZUS scheme used by Australian farmers reveals the dangers of trading soil carbon to tackle climate change<figure><img src="https://images.theconversation.com/files/407840/original/file-20210623-27-13co042.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5607%2C3732&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Soil carbon is in the spotlight in Australia. A key plank in the Morrison government’s <a href="https://www.industry.gov.au/sites/default/files/September%202020/document/first-low-emissions-technology-statement-2020.pdf">technology-led</a> emissions reduction policy, it involves changing farming techniques so soils store more carbon from the atmosphere.</p>
<p>Farmers can encourage and accelerate this process through methods that increase plant production, such as improving nutrient management or sowing permanent pastures. For each unit of atmospheric carbon they remove in this way, farmers can earn “carbon credits” to be sold in emissions trading markets.</p>
<p>But not all carbon credits are created equal. In one high-profile <a href="https://www.beefcentral.com/news/aus-cattle-company-makes-global-carbon-credit-sale-to-microsoft/">deal</a> in January, an Australian farm sold soil carbon credits to Microsoft under a scheme based in the United States. We analysed the methodology behind the trade, and found some increases in soil carbon claimed under the scheme were far too optimistic. </p>
<p>It’s just one of several problems raised by the sale of carbon credits offshore. If not addressed, the credibility of carbon trading will be undermined. Ultimately the climate - and the planet - will be the loser.</p>
<figure class="align-center ">
<img alt="sunset on farm with cattle and trees" src="https://images.theconversation.com/files/407842/original/file-20210623-21-k64xg8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/407842/original/file-20210623-21-k64xg8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407842/original/file-20210623-21-k64xg8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407842/original/file-20210623-21-k64xg8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407842/original/file-20210623-21-k64xg8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407842/original/file-20210623-21-k64xg8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407842/original/file-20210623-21-k64xg8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The integrity of soil carbon trading must be assured.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>What is soil carbon trading?</h2>
<p>Plants naturally remove carbon dioxide (CO₂) from the air through photosynthesis. As plants decompose, carbon-laden organic matter is added to the soil. If more organic matter is added than is lost, soil carbon levels increase. </p>
<p>Carbon trading schemes require the increase in soil carbon levels to be measured. The measurement methods are well-established, but can be costly and complex because they involve collecting and analysing large numbers of soil samples. And different carbon credit schemes measure the change in different ways - some more robust than others.</p>
<p>The Australian government’s Emissions Reduction Fund has a rigorous approach to soil sampling, laboratory analysis and calculation of credits. This ensures only genuine removals of atmospheric carbon are rewarded, in the <a href="http://www.cleanenergyregulator.gov.au/OSR/ANREU/types-of-emissions-units/australian-carbon-credit-units">form of</a> “Australian Carbon Credit Units”.</p>
<p>Farmers can choose other schemes under which to earn carbon credits, such as the US-based carbon offset <a href="https://www.regen.network/">platform</a> Regen Network.</p>
<p>Regen Network’s method for estimating soil carbon largely involves collecting data via satellite imagery. The extent of physical on-the-ground soil sampling is limited. </p>
<p>Regen Network issues “CarbonPlus credits” to farmers deemed to have increased soil carbon stores. Farmers then sell these credits on the Regen Network trading platform.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/nJ3IFYuYlcY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Regen Network video explaining its remote sensing methods.</span></figcaption>
</figure>
<h2>‘A number of concerns’</h2>
<p>It was Regen Network which sold Microsoft the soil carbon credits generated by an Australian farm, Wilmot Station. Wilmot is owned by the Macdoch Group, and other Macdoch properties have also claimed carbon credits under the Regen Scheme. </p>
<p>Regen Network should be applauded for making its methods and calculations available online. And we appreciate Regen’s open, collaborative approach to developing its methods. </p>
<p>However, we have reviewed their documents and have a number of concerns:</p>
<ul>
<li><p>the dry weight of soil in a known volume, also known as “bulk density”, is a key factor in calculating soil carbon stocks. Rather than bulk density being measured from field samples, it was calculated using an equation. We examined this method and determined it was far less reliable than field sampling</p></li>
<li><p>Estimates of soil carbon were not adjusted for gravel content. Because gravel contains no carbon, carbon stock may have been overestimated</p></li>
<li><p>The remote sensing used by Regen Network involved assessment of vegetation cover via satellite imagery, from which soil carbon levels were estimated. However, vegetation cover obscures soil, and research has found predictions of soil carbon using this method are highly <a href="https://www.mdpi.com/2072-4292/11/14/1683/htm">uncertain</a>.</p></li>
</ul>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/the-morrison-government-wants-to-suck-co-out-of-the-atmosphere-here-are-7-ways-to-do-it-144941">The Morrison government wants to suck CO₂ out of the atmosphere. Here are 7 ways to do it</a>
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<p>Wilmot increased soil carbon, or “sequestration”, through changes to grazing and pasture management. The resulting rates of carbon storage calculated by Regen Network were extremely high – 7,660 tonnes of carbon over 1,094 hectares. This amounts to 7 tonnes of carbon per hectare from <a href="https://regen-registry.s3.amazonaws.com/projects/wilmot/Wilmot+Monitoring+Report+2019.pdf">2018 to 2019</a>. </p>
<p>These results are not consistent with our experience of what is possible through pasture management. For example, the CSIRO has <a href="https://publications.csiro.au/publications/publication/PIcsiro:EP10121">documented</a> soil carbon increases of 0.1 to 0.3 tonnes of carbon per hectare per year in Australia from a range of methods to increase pasture production.</p>
<p>We believe inaccurate methods have led to the carbon increase being overestimated. Thus, it appears excess carbon credits may have been awarded. </p>
<p>Many carbon trading schemes apply <a href="https://www.offsetguide.org/high-quality-offsets/">rules</a> to ensure integrity is maintained. These include:</p>
<ul>
<li><p>an “additionality test” to ensure the extra carbon storage in the soil would not have happened anyway. It would prevent, for example, farmers claiming credits for practices they adopted in the past</p></li>
<li><p>ensuring sequestered carbon is maintained over time</p></li>
<li><p>disallowing double-counting of credits – for example, by preventing a country claiming credits that have been sold offshore.</p></li>
</ul>
<p>The Emissions Reduction Fund and other well-recognised international schemes, such as <a href="https://verra.org/project/vcs-program/">Verra</a> and <a href="https://www.goldstandard.org/">Gold Standard</a>, apply these rules stringently. Regen Network’s safeguards are less rigorous.</p>
<p>Responses to these claims from Regen Network and Macdoch Group can be found at the end of this article. A full response from Regen can also be found <a href="https://docs.google.com/document/d/1neVVUoyoUsyD_UQM-xBzQ-cAvf3DxqNmHhrZxMmWzSg/edit">here</a>.</p>
<figure class="align-center ">
<img alt="diagram. showing arms, money, laptop and leaves over world map" src="https://images.theconversation.com/files/407841/original/file-20210623-13-97dzfp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/407841/original/file-20210623-13-97dzfp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=257&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407841/original/file-20210623-13-97dzfp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=257&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407841/original/file-20210623-13-97dzfp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=257&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407841/original/file-20210623-13-97dzfp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=323&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407841/original/file-20210623-13-97dzfp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=323&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407841/original/file-20210623-13-97dzfp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=323&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Carbon trading is a way for farmers to make money by changing their land management practices.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Not in the national interest?</h2>
<p>Putting aside the problems noted above, the offshore sale of soil carbon credits generated by Australian farmers raises other concerns.</p>
<p>First, selling credits offshore means Australia loses out, by not being able to claim the abatement towards our own <a href="https://www.environment.nsw.gov.au/topics/climate-change/net-zero-plan">government</a> and <a href="https://www.mla.com.au/research-and-development/Environment-sustainability/carbon-neutral-2030-rd/cn30/">industry</a> targets.</p>
<p>Second, soil carbon does not have unlimited emissions reduction potential. The quantum of carbon that can be stored in each hectare of soil is <a href="https://onlinelibrary.wiley.com/doi/10.1111/ejss.12194">constrained</a>, and limited by factors such as land availability and <a href="https://www.sciencedirect.com/science/article/abs/pii/S0016706118301216">climate change</a>. So measures to increase soil carbon should not detract from society’s efforts to reduce emissions from fossil fuel use.</p>
<p>And third, ensuring carbon remains in soil long after it’s deposited is a <a href="https://pubmed.ncbi.nlm.nih.gov/32148267/">challenge</a> because soil microbes break down organic matter. Carbon credit schemes commonly manage this by requiring a “buffer” of unsold credits. If stored carbon is lost, farmers must relinquish credits from the buffer. </p>
<p>If the loss is greater than the buffer, credits must be purchased to make up the difference. This exposes farmers to financial risk, especially if <a href="https://www.greenbiz.com/article/carbon-offset-prices-set-increase-tenfold-2030">carbon prices rise</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/we-need-more-carbon-in-our-soil-to-help-australian-farmers-through-the-drought-102991">We need more carbon in our soil to help Australian farmers through the drought</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="farmer sits on rock" src="https://images.theconversation.com/files/407843/original/file-20210623-13-jvp69u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/407843/original/file-20210623-13-jvp69u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/407843/original/file-20210623-13-jvp69u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/407843/original/file-20210623-13-jvp69u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/407843/original/file-20210623-13-jvp69u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/407843/original/file-20210623-13-jvp69u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/407843/original/file-20210623-13-jvp69u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Poorly managed carbon trading schemes can put farmers at financial risk.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Getting it right</h2>
<p>Soil carbon is a promising way for Australia to substantially reduce its emissions. But methods used to measure gains in soil carbon must be accurate. </p>
<p>Carbon markets must be regulated to ensure credit is awarded for genuine abatement, and risks to farmers are limited. And the extent to which offshore carbon markets prevent Australia from meeting its own obligations to reduce emissions should be clarified and managed.</p>
<p>Improving the integrity of soil carbon trading will have benefits beyond emissions reduction. It will also improve soil health and farm productivity, helping agriculture become more resilient under climate change.</p>
<hr>
<h2>Regen Network response</h2>
<p>Regen Network provided The Conversation with a response to concerns raised in this article. The full nine-page statement provided by Regen Network is available <a href="https://docs.google.com/document/d/1neVVUoyoUsyD_UQM-xBzQ-cAvf3DxqNmHhrZxMmWzSg/edit">here</a>.</p>
<p>The following is a brief summary of Regen Network’s statement:</p>
<p><strong>- Limited on-ground soil sampling</strong>: Regen Network said its usual minimum number of soil samples was not reached in the case of Wilmot Station, because historical soil samples - taken before the project began - were used. To compensate for this, relevant sample data from a different farm was combined with data from Wilmot.</p>
<p>“We understand the use of ancillary data does not follow best practice and our team is working hard to ensure future projects are run using a sufficient number of samples,” Regen Network said.</p>
<p><strong>- Bulk density:</strong> Regen Network said the historical sample data from Wilmot did not include “bulk density” measurements needed to estimate carbon stocks, which required “deviations” from its usual methodology. However the company was taking steps to ensure such estimates in future projects “can be provided with higher degrees of accuracy”.</p>
<p><strong>- Gravel content:</strong> Regen Network said lab reports for soil samples included only the weight, not volume, of gravel present. “Best sampling practice should include the gravel volume as an essential parameter for accurate bulk density measurements. We will make sure to address this in our next round of upgrades and appreciate the observation!” the statement said.</p>
<p><strong>- Remote sensing of vegetation:</strong> Regen Network said it did not use vegetation assessment at Wilmot station. It tested a vegetation assessment index at another property and found it ineffective at estimating soil carbon. At Wilmot station Regen used so-called individual “spectral bands” to estimate soil carbon at locations where on-ground sampling was not undertaken.</p>
<p><strong>- Sequestration rates at Wilmot:</strong> Regen Network said while it was difficult to directly compare local sequestration rates across climatic and geologic zones, the sequestration rates for the projects in question “fall within the relatively wide range of sequestration rates” reported in key scientific studies.</p>
<p>Regen Network said its methodology “provides a conservative estimate on the final number of credits issued”. Its statement outlines the steps taken to ensure soil carbon levels are not overestimated.</p>
<p><strong>- Integrity safeguards:</strong> Regen Network said it employs standards “based both on existing standards of reputable programs […] and inputs from project developers, in order to come up with a standard that not only is rigorous but also practical”. Regen Network takes steps to ensure additionality and permanence of carbon stores, as well as avoid double counting of carbon credits generated through their platform.</p>
<p>A more detailed response from Regen Network can be found <a href="https://docs.google.com/document/d/1neVVUoyoUsyD_UQM-xBzQ-cAvf3DxqNmHhrZxMmWzSg/edit">here</a>.</p>
<hr>
<h2>Wilmot Station response</h2>
<p>Wilmot Station provided the following response from Alasdair Macleod, chairman of Macdoch Group. It has been edited for brevity:</p>
<p><em>We entered into the deals with Regen Network/Microsoft because we wanted to give a hint of the huge potential that we believe exists for farmers in Australia and globally to sequester soil carbon which can be sold through offset markets or via other methods of value creation.</em></p>
<p><em>Whilst we recognise that the soil carbon credits generated on the Macdoch Group properties in the Regen Network/Microsoft deal will not be included in Australia’s national carbon accounts, it is our hope that over time the regulated market will move towards including appropriately rigorous transactions such as these in some form.</em></p>
<p><em>At the same time we have also been working closely with the Australian government, industry organisations, academia and other interested parties on Macdoch Group properties to develop appropriate soil carbon methodologies under the government’s Climate Solutions Fund.</em></p>
<p><em>This is because carbon measurement methodologies are an evolving science. We have always acknowledged and will welcome improvements that will be made over the coming years to the methodologies utilised by both the voluntary and regulated markets.</em></p>
<p><em>In any event it has become clear that there is huge demand from the private sector for offset deals of this nature and we will continue to work towards ensuring that other farmers can take advantage of the opportunities that will become available to those that are farming in a carbon-friendly fashion.</em></p><img src="https://counter.theconversation.com/content/161358/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Aaron Simmons is a Technical Specialist in Climate Change Mitigation with the NSW Department of Primary Industries and an Adjunct Senior Research Fellow with The University of New England. Aaron has received funding from Australian Wool Innovation, Grains Research and Development Corporation, Cotton Research and Development Corporation, Dairy Australia and the Commonwealth government. </span></em></p><p class="fine-print"><em><span>Annette Cowie is a Senior Principal Research Scientist in the Climate Branch at the NSW Department of Primary Industries, and Adjunct Professor in the School of Environmental and Rural Science at the University of New England. She has received funding for soil carbon research from NSW and Commonwealth government programs. Annette is a member of Soil Science Australia, a not-for-profit, professional association for soil scientists and people interested in the responsible management of Australia’s soil resources.</span></em></p><p class="fine-print"><em><span>Brian Wilson is a member of academic staff and researcher at the University of New England and a Principal Research Scientist with NSW State Government. He has received research income from a range of State and Commonwealth organisations to engage in research relating to soil carbon.</span></em></p><p class="fine-print"><em><span>Mark Farrell has received funding for soil carbon research from Commonwealth, State and industry programmes. He is a member of Soil Science Australia, a not-for-profit, professional association for soil scientists and people interested in the responsible management of Australia's soil resources.</span></em></p><p class="fine-print"><em><span>Matthew Tom Harrison is an Associate Professor and Systems Modelling Team Leader at the University of Tasmania. He receives funding from the Commonwealth and Tasmanian Government, as well as Meat & Livestock Australia. His research examines pathways for improving the sustainability of agricultural systems, including avenues for greenhouse gas emissions mitigation through soil carbon sequestration.</span></em></p><p class="fine-print"><em><span>Peter Grace has received funding from federal government sources and Rural Development Corporations with respect to sustainable agricultural systems and reducing greenhouse gas emissions. </span></em></p><p class="fine-print"><em><span>Richard Eckard receives funding from Commonwealth Government, as well as Meat & Livestock Australia and Dairy Australia. </span></em></p><p class="fine-print"><em><span>Vanessa Wong receives funding from the Victorian State Government and the Australian Research Council. She is currently the President of Soil Science Australia, a not-for-profit, professional association for soil scientists and people interested in the responsible management of Australia’s soil resources </span></em></p><p class="fine-print"><em><span>Warwick Badgery is a Research Leader in Rangelands and Pasture with the NSW Department of Primary Industries and has honorary positions with Melbourne University and China Agricultural University. He receives funding from the Federal Government, Meat and Livestock Australia and the food Agility CRC for agricultural systems and soil carbon research. </span></em></p>If problems in such schemes are not addressed, the credibility of soil carbon trading will be undermined. Ultimately the climate - and the planet - will be the loser.Aaron Simmons, Adjunct Senior Research Fellow, University of New EnglandAnnette Cowie, Adjunct Professor, University of New EnglandBrian Wilson, Associate Professor, University of New EnglandMark Farrell, Principal Research Scientist, CSIROMatthew Tom Harrison, Associate Professor of Sustainable Agriculture, University of TasmaniaPeter Grace, Professor of Global Change, Queensland University of TechnologyRichard Eckard, Professor & Director, Primary Industries Climate Challenges Centre, The University of MelbourneVanessa Wong, Associate Professor, Monash UniversityWarwick Badgery, Research Leader Pastures an Rangelands, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1609272021-06-07T20:07:35Z2021-06-07T20:07:35ZTasmania’s reached net-zero emissions and 100% renewables – but climate action doesn’t stop there<figure><img src="https://images.theconversation.com/files/404741/original/file-20210607-8878-wfzk4q.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3498%2C2292&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Getting to net-zero greenhouse gas emissions and 100% renewable energy might seem the end game for climate action. But what if, like Tasmania, you’ve already ticked both those goals off your list?</p>
<p>Net-zero means emissions are still being generated, but they’re offset by the same amount elsewhere. <a href="http://www.premier.tas.gov.au/releases/tasmania_achieves_zero_net_emissions_for_the_first_time">Tasmania reached net-zero</a> in 2015, because its vast forests and other natural landscapes absorb and store more carbon each year than the state emits.</p>
<p>And in November last year, Tasmania became fully powered by <a href="http://www.premier.tas.gov.au/site_resources_2015/additional_releases/tasmania_surges_to_100_renewable_energy">renewable electricity</a>, thanks to the island state’s wind and hydro-electricity projects.</p>
<p>The big question for Tasmania now is: what comes next? Rather than considering the job done, it should seize opportunities including more renewable energy, net-zero industrial exports and forest preservation – and show the world what the other side of net-zero should look like.</p>
<figure class="align-center ">
<img alt="electricity transmission lines" src="https://images.theconversation.com/files/404744/original/file-20210607-27-152ki66.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/404744/original/file-20210607-27-152ki66.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/404744/original/file-20210607-27-152ki66.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/404744/original/file-20210607-27-152ki66.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/404744/original/file-20210607-27-152ki66.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/404744/original/file-20210607-27-152ki66.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/404744/original/file-20210607-27-152ki66.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Hydro-electric power and wind energy mean Tasmania runs on 100% renewable energy.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>A good start</h2>
<p>The Tasmanian experience shows emissions reduction is more straightforward in some places than others. </p>
<p>The state’s high rainfall and mountainous topography mean it has abundant hydro-electric resources. And the state’s windy north is <a href="https://www.abc.net.au/news/2021-01-06/foreign-investment-in-tasmanian-wind-farms-raising-concerns/13036164">well suited</a> to wind energy projects.</p>
<p>What’s more, <a href="https://www.stategrowth.tas.gov.au/__data/assets/pdf_file/0014/142313/Forestry_Fact_Sheet_2019.pdf">almost half</a> the state’s 6.81 million hectares comprises forest, which acts as a giant carbon “sink” that sucks up dioxide (CO₂) from the atmosphere. </p>
<p>Given Tasmania’s natural assets, it makes sense for the state to go further on climate action, even if its goals have been met. </p>
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<em>
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Read more:
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<p>The Tasmanian government has gone some way to recognising this, by legislating a target of <a href="http://www.premier.tas.gov.au/site_resources_2015/additional_releases/renewable_energy_target_to_deliver_for_tasmania">200% renewable electricity</a> by 2040. </p>
<p>Under the target, Tasmania would produce twice its current electricity needs and export the surplus. It would be delivered to the mainland via the proposed A$3.5 billion <a href="https://www.marinuslink.com.au/news/">Marinus Link</a> cable to be built between Tasmania and Victoria. The 1,500 megawatt cable would bolster the existing 500 megawatt Basslink cable.</p>
<p>But Tasmania’s climate action should not stop there.</p>
<figure class="align-center ">
<img alt="artist impression of marinus link" src="https://images.theconversation.com/files/404732/original/file-20210607-80132-1qv2h20.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/404732/original/file-20210607-80132-1qv2h20.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=366&fit=crop&dpr=1 600w, https://images.theconversation.com/files/404732/original/file-20210607-80132-1qv2h20.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=366&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/404732/original/file-20210607-80132-1qv2h20.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=366&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/404732/original/file-20210607-80132-1qv2h20.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=459&fit=crop&dpr=1 754w, https://images.theconversation.com/files/404732/original/file-20210607-80132-1qv2h20.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=459&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/404732/original/file-20210607-80132-1qv2h20.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=459&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The Marinus Link would provide a second electricity connection from Tasmania to the mainland.</span>
<span class="attribution"><span class="source">www.marinuslink.com.au</span></span>
</figcaption>
</figure>
<h2>Other opportunities await</h2>
<p>Tasmania can use its abundant renewable electricity to decarbonise existing industrial areas. It can also create new, <a href="https://bze.org.au/research_release/renewable-energy-industrial-precincts/">greener industrial precincts</a> – clusters of manufacturers powered by renewable electricity and other zero-emissions fuels such as <a href="https://theconversation.com/for-hydrogen-to-be-truly-clean-it-must-be-made-with-renewables-not-coal-128053">green hydrogen</a>.</p>
<p>Zero-emission hydrogen, aluminium and other goods produced in these precincts will become increasingly sought after by countries and other states with their own net-zero commitments.</p>
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<p>Tasmania’s vast forests could be an additional source of economic value if they were preserved and expanded, rather than logged. As well as supporting tourism, preserving forests could enable Tasmania to sell carbon credits to other jurisdictions and businesses seeking to offset their emissions, such as through the federal government’s <a href="http://www.cleanenergyregulator.gov.au/ERF/About-the-Emissions-Reduction-Fund">Emissions Reduction Fund</a>.</p>
<p>The ocean surrounding Tasmania also presents net-zero economic opportunities. For example, local company Sea Forest is <a href="https://www.minister.industry.gov.au/ministers/karenandrews/media-releases/seaweed-driving-down-emissions-and-driving-jobs">developing a seaweed product</a> to be added to the feed of livestock, dramatically reducing the methane they emit.</p>
<figure class="align-center ">
<img alt="logs on a truck" src="https://images.theconversation.com/files/404735/original/file-20210607-80132-1tqgup5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/404735/original/file-20210607-80132-1tqgup5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/404735/original/file-20210607-80132-1tqgup5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/404735/original/file-20210607-80132-1tqgup5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/404735/original/file-20210607-80132-1tqgup5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/404735/original/file-20210607-80132-1tqgup5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/404735/original/file-20210607-80132-1tqgup5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Retaining, rather than logging, Tasmania’s forests presents an economic opportunity.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Concrete targets are needed</h2>
<p>The Tasmanian government has commissioned a <a href="http://dpac.tas.gov.au/divisions/climatechange/Climate_Change_Priorities/review_of_the_climate_change_act#:%7E:text=The%20Climate%20Change%20(State%20Action,consultation%20with%20the%20Tasmanian%20community.">review</a> of its <a href="https://www.legislation.tas.gov.au/view/html/inforce/current/act-2008-036">climate change legislation</a>, and is also revising its <a href="http://www.dpac.tas.gov.au/divisions/climatechange/tasmanias_climate_change_action_plan_20172021">climate change action plan</a>.</p>
<p>These updates give Tasmania a chance to be a global model for a post-net-zero world. But without firm action, Tasmania risks sliding backwards.</p>
<p>While having reached net-zero, the state has not legislated or set a requirement to maintain it. The state’s <a href="http://www.dpac.tas.gov.au/divisions/climatechange/Climate_Change_Priorities/reducing_emissions">current legislated</a> emission target is a 60% reduction by 2050 on 1990 levels – which, hypothetically, means Tasmania could increase its emissions in future.</p>
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<p>Also, despite reaching net-zero emissions, Tasmania still emits more than <a href="http://www.dpac.tas.gov.au/divisions/climatechange/climate_change_in_tasmania/tasmanias_emissions#:%7E:text=The%20Government%20has%20also%20committed,four%20years%20in%20a%20row">8.36 million tonnes</a> of CO₂ each year from sources such as transport, natural gas use, industry and agriculture. Tasmania’s emissions from all sectors other than electricity and land use have <a href="https://ageis.climatechange.gov.au/">increased</a> by 4.5% since 2005. </p>
<p>Without a net-zero target set in law – and a plan to stay there – these emissions could overtake those drawn down by Tasmania’s forests. In fact, <a href="http://www.dpac.tas.gov.au/__data/assets/pdf_file/0011/573095/net_zero_emissions_background_Paper_-_Final.pdf">a background paper</a> prepared for the Tasmanian government shows the state’s emissions may rise in the coming years and stay “positive” until 2040 or later.</p>
<p>The legislation update should also include a process to set emissions targets for each sector of the economy, as <a href="https://www.climatechange.vic.gov.au/__data/assets/pdf_file/0027/55287/CC-Act-2017_Fact-Sheet_Emissions-Reduction-Pledges_v2.pdf">Victoria has done</a>. It should also set ambitious targets for “negative” emissions – which means sequestering more CO₂ than is emitted.</p>
<figure class="align-center ">
<img alt="Industrial plant billowing smoke" src="https://images.theconversation.com/files/404738/original/file-20210607-52826-1usc9o0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/404738/original/file-20210607-52826-1usc9o0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/404738/original/file-20210607-52826-1usc9o0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/404738/original/file-20210607-52826-1usc9o0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/404738/original/file-20210607-52826-1usc9o0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/404738/original/file-20210607-52826-1usc9o0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/404738/original/file-20210607-52826-1usc9o0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Tasmania must cut emissions from industry and other sectors.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Action on all fronts</h2>
<p>Under the <a href="https://unfccc.int/process-and-meetings/the-paris-agreement/the-paris-agreement">Paris Agreement</a>, the world is pursuing efforts to limit global warming to 1.5°C this century. For Australia to be in line with this goal, <a href="https://www.climateworksaustralia.org/resource/decarbonisation-futures-solutions-actions-and-benchmarks-for-a-net-zero-emissions-australia/">it must</a> reach net-zero by the mid-2030s.</p>
<p>Meeting this momentous task requires action on all fronts, in all jurisdictions. Bigger states and territories are aiming for <a href="https://www.climatechange.vic.gov.au/victorias-greenhouse-gas-emissions-reduction-targets">substantial</a> emissions reductions this decade. Tasmania must at least keep its emissions net-negative, and decrease them further.</p>
<p>Tasmania has a golden opportunity. With the right policies, the state can solidify its climate credentials and create a <a href="https://www.abc.net.au/news/2021-04-18/tasmanian-economy-good-report-card-but-challenges-head/100071028">much-needed</a> economic boost as the world transitions to a low-carbon future.</p><img src="https://counter.theconversation.com/content/160927/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rupert Posner is part of ClimateWorks Australia, which works within the Monash Sustainable Development Institute. ClimateWorks Australia receives its core funding from philanthropic foundations and also undertakes projects which attract funding from industry and government departments and agencies.</span></em></p><p class="fine-print"><em><span>Simon Graham is part of ClimateWorks Australia, which works within the Monash Sustainable Development Institute. ClimateWorks Australia receives its core funding from philanthropic foundations and also undertakes projects which attract funding from industry and government departments and agencies.</span></em></p>Rather than considering the job done, Tasmania should seize opportunities including renewable energy, net-zero industrial exports and forest preservation.Rupert Posner, Systems Lead - Sustainable Economies, Climateworks CentreSimon Graham, Senior Analyst, Climateworks CentreLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1616892021-05-28T09:14:30Z2021-05-28T09:14:30ZClimate change: six priorities for pulling carbon out of the air<figure><img src="https://images.theconversation.com/files/403179/original/file-20210527-19-pnquvv.jpg?ixlib=rb-1.1.0&rect=401%2C290%2C3239%2C2471&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/carbon-capture-technology-net-co2-footprint-1907627452">Dmitry Kovalchuk/Shutterstock</a></span></figcaption></figure><p>To reach net zero emissions by 2050, global emissions <a href="https://www.ipcc.ch/sr15/chapter/spm/">must be cut</a> faster and deeper than the world has yet managed. But even then, some hard-to-treat sources of pollution – in aviation, agriculture and cement making – may linger for longer than we would like. It will take time for clean alternatives to arrive and replace them. </p>
<p>That means the world also needs to find and ramp up ways of taking CO₂ out of the atmosphere to stabilise the climate. Just meeting the UK’s net zero target is likely to require the removal of <a href="https://www.theccc.org.uk/publication/sixth-carbon-budget/">100 million tonnes of CO₂ a year</a>, similar in size to current emissions from the country’s largest-emitting sector, road transport, but in reverse.</p>
<p>The UK government’s announcement of <a href="https://www.ukri.org/news/uk-invests-over-30m-in-large-scale-greenhouse-gas-removal/">£31.5 million</a> (US$44.7 million) in support for research and development of carbon removal is welcome. And while trials of new tech will help, there are many social issues that need to be tackled if removing greenhouse gases is to succeed.</p>
<p>Done right, carbon removal could be the perfect accompaniment to emissions cuts, bringing the climate back into balance. Done badly, it could be a dangerous distraction.</p>
<figure class="align-center ">
<img alt="Three smoke stacks belching white smoke from a coal-fired power plant." src="https://images.theconversation.com/files/403170/original/file-20210527-19-lx7t5c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/403170/original/file-20210527-19-lx7t5c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/403170/original/file-20210527-19-lx7t5c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/403170/original/file-20210527-19-lx7t5c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/403170/original/file-20210527-19-lx7t5c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/403170/original/file-20210527-19-lx7t5c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/403170/original/file-20210527-19-lx7t5c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Cutting emissions is vital. So is carbon removal.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/industrial-smoke-stack-coal-power-plant-607164341">Kamilpetran/Shutterstock</a></span>
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<h2>Getting removal right</h2>
<p>Greenhouse gases can be removed from the atmosphere in several different ways. CO₂ can be captured by plants as they grow or absorbed by soils, minerals or chemicals, and locked up in the biosphere, oceans, underground, or even in long-lived products such as construction materials (including timber or aggregates).</p>
<p>These stores <a href="https://royalsociety.org/topics-policy/projects/greenhouse-gas-removal/">vary</a> in size and stability, and methods for getting carbon into them vary in cost and readiness. Trees, for instance, are literally a shovel-ready way to soak up carbon with many additional benefits. But the carbon they store can be released by fires, pests or logging. Storing CO₂ underground offers a more stable reservoir and could hold <a href="https://royalsociety.org/topics-policy/projects/greenhouse-gas-removal/">100 times as much</a>, but methods of injecting it from the air are expensive and at an early stage of development. Nevertheless, a raft of <a href="https://www.gov.uk/government/publications/direct-air-capture-and-other-greenhouse-gas-removal-technologies-competition/projects-selected-for-phase-1-of-the-direct-air-capture-and-greenhouse-gas-removal-programme">innovations</a>, <a href="https://www.xprize.org/prizes/elonmusk">competitions</a> and <a href="https://carbonplan.org/research/cdr-database">start-ups</a> are emerging.</p>
<p>Some experts worry that carbon removal could prove to be a mirage – particularly at the massive scales assumed in some pathways for reaching net zero – which distracts from the critical task of reducing emissions. So how do we get removals right?</p>
<p>As the scientists who will lead a national greenhouse gas removal hub, we’ve sketched out six priorities.</p>
<h2>1. A clear vision</h2>
<p>The UK government has yet to decide how much CO₂ it wants to remove from the atmosphere, the specific methods it prefers, and whether 2050 is an endpoint or a stepping stone to more removals beyond. A clear vision would help people see the merits of investing to remove CO₂, while also indicating which emissions sources should be stopped entirely.</p>
<h2>2. Public support</h2>
<p>Carbon removal at the scales under discussion will have big implications for communities and the environment. Entire landscapes and livelihoods will change. The government already aims to <a href="https://www.gov.uk/government/news/39-million-to-drive-innovative-tree-planting">plant enough trees</a> to cover twice the area of Bristol each year. </p>
<p>These changes need to offer <a href="https://royalsocietypublishing.org/doi/full/10.1098/rstb.2019.0120">other benefits</a> and align with the values of local people. People care not only about the removal techniques themselves, but also how <a href="https://www.nature.com/articles/s41467-019-08592-5">they are funded and supported</a>, and will want to see that reducing emissions remains <a href="https://www.nature.com/articles/s41558-020-0823-z?proof=t">the priority</a>. </p>
<p>Consultation is vital. Democratic processes, such as citizen assemblies, can help to find solutions that are attractive to different communities, increasing their legitimacy.</p>
<h2>3. Innovation</h2>
<p>The types of approaches that remove CO₂ permanently are at an early stage of development and cost hundreds of pounds per tonne of CO₂ removed. They are more expensive than most decarbonisation measures such as energy efficient lighting, insulation, solar and wind power or electric cars. Government support for research and development, and policies to encourage deployment are also crucial to stimulate innovation and bring down costs. </p>
<h2>4. Incentives</h2>
<p>How does a business earn a profit from removing CO₂ from the air? Except for <a href="https://www.gov.uk/guidance/create-woodland-overview#woodland-creation-funding-and-grants">trees</a>, there are no long-term, government-backed incentives for the removal and storage of carbon.</p>
<p>The UK government can learn from efforts in other countries. The <a href="https://www.globalccsinstitute.com/resources/publications-reports-research/the-lcfs-and-ccs-protocol-an-overview-for-policymakers-and-project-developers/">45Q tax rebate and Californian Low-Carbon Fuel Standard</a> and the Australian <a href="https://www.agriculture.gov.au/water/policy/carbon-farming-initiative">Carbon Farming Initiative</a> both incentivise businesses to capture and store CO₂.</p>
<p>Leaving the EU Common Agriculture Policy means the UK has its own opportunity to pay farmers to put carbon into their soils, trees and crops.</p>
<h2>5. Monitoring, reporting and verifying</h2>
<p>This is the vital but unglamorous work of ensuring carbon removal is properly documented and accurately measured. Without it, citizens would rightly worry whether any of this was real, and whether governments were simply handing out public money to companies for nothing in return.</p>
<p>Monitoring, reporting and verifying carbon storage in soil is a major challenge, requiring a <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.14815">complex system</a> of in-field sampling, satellites and models. Even for trees there are <a href="https://www.nature.com/articles/s41558-018-0283-x">gaps in international reporting</a> in many countries, and <a href="https://www.globalccsinstitute.com/wp-content/uploads/2021/01/Carbon-Removal-with-CCS-Technologies-Global-CCS-Institute-3.pdf">no agreed method</a> for reporting <a href="https://www.iea.org/reports/direct-air-capture">direct air capture</a> and storage, which uses chemicals to absorb CO₂ from the air.</p>
<h2>6. Decision-making</h2>
<p>A lot of information about CO₂ removal resides in academic literature and focuses on global-scale scenarios. But actually doing it will involve people ranging from local farmers to international financiers. All will need tools to help them make better decisions, from easy-to-read <a href="https://cdrprimer.org/">manuals</a> to improved <a href="https://www.nature.com/articles/s41467-019-10842-5">models</a>.</p>
<p>These priorities will guide our research, and will be things to look out for in the government’s emerging removal strategy. They need to involve businesses and citizens, not just policymakers and scientists.</p>
<p>Unfortunately, it is so late in the day that we can’t afford to get this wrong. But we are optimistic that there is plenty of scope to get it right.</p><img src="https://counter.theconversation.com/content/161689/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cameron Hepburn receives funding from the UK government and UK research councils for work on accelerating the energy transition and on greenhouse gas removal. He is a member of the External Advisory Board of Shell plc, and the Advisory Board of Sarasin's Climate Active Fund. </span></em></p><p class="fine-print"><em><span>Steve Smith receives funding from the UK research councils for work on greenhouse gas removal. </span></em></p>New UK-wide trials aim to discover the best ways to suck carbon from the air.Cameron Hepburn, Professor of Environmental Economics, University of OxfordSteve Smith, Executive Director, Oxford Net Zero, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1581002021-04-16T14:43:52Z2021-04-16T14:43:52ZUK land now stores 7% more carbon than 300 years ago – what that means for the environment<figure><img src="https://images.theconversation.com/files/395460/original/file-20210416-23-qpwjh5.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6720%2C4466&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/golden-sunset-sunrise-light-on-lone-1938816559">Stephen Bridger/Shutterstock</a></span></figcaption></figure><p>Limiting global warming to 1.5°C and avoiding the worst effects of climate change will take more than eliminating greenhouse gas emissions. The world will also need to capture and store a lot of carbon dioxide (CO₂) from the atmosphere. </p>
<p>Land offers one natural way of doing this. The soil and everything that grows in it, including all plants and trees, represents <a href="https://www.ipcc.ch/site/assets/uploads/2018/02/WG1AR5_Chapter06_FINAL.pdf">about half of all</a> organic carbon globally. This is the carbon that’s bound up in living and decaying matter, as opposed to rocks and minerals. Depending on how humans treat it, the land can act as a net sink or source of carbon, either slowing or accelerating climate change. Planting trees can lock carbon away while deforestation and tilling the soil in agriculture can release it. </p>
<p>Since the dawn of the Industrial Revolution, the UK has emitted about <a href="https://ourworldindata.org/co2/country/united-kingdom?country=%7EGBR">77 billion tonnes of CO₂</a>. But how much has the country’s land area absorbed over the same period? <a href="https://www.sciencedirect.com/science/article/pii/S2213305421000126#bib0030">Our new study</a> set out to find an estimate by modelling natural cycles of carbon, nitrogen and phosphorus. </p>
<p>We found that over the last 300 years, the UK’s land carbon store has grown by about 7%, with vegetation storing 13% more carbon and soil 5% more than it did in the 18th century. Carbon storage increased most in forests and heathlands, and fell by the greatest amount in areas which were converted to arable farmland. </p>
<p>So the UK’s land carbon sink is working harder today than it was three centuries ago. Is that a good thing? As it turns out, not really. </p>
<h2>Right direction, wrong reason</h2>
<p>Since 1700, land carbon storage in the UK has increased by 233 million tonnes. That’s equivalent to 855 million tonnes of CO₂. The UK is one of the world’s largest historical emitters of carbon, so this only equates to 1.1% of the nation’s estimated emissions over the same period. But there’s a bigger problem: land-based carbon stores in the UK are unlikely to continue growing in the future for several reasons. </p>
<p>The biggest driver of the increase was pollution. When fertilisers are used in agriculture or fossil fuels are burned, these processes release reactive forms of nitrogen into the atmosphere. This is deposited on the land when it rains. </p>
<p>Since the availability of nitrogen normally limits how much plants can grow, this additional nitrogen <a href="https://theconversation.com/carbon-catch-22-the-pollution-in-our-soil-78718">acts like extra fertiliser</a>, boosting the amount of carbon that vegetation can capture. More leaf and plant litter is produced, which rots and delivers carbon to the soil.</p>
<p>But areas which were converted to farmland showed steep declines in the size of their carbon stores. When land is cleared of vegetation, the carbon stored in it is lost. Even though farmers add more nitrogen to arable land through fertilisers, the crop plants that grow are harvested, and so their carbon doesn’t end up stored in the soil.</p>
<p>The net increase in the carbon that the UK’s land is storing came from the gains across natural habitats fertilised by nitrogen. These were only slightly larger than the carbon losses from land converted for agriculture. And plants won’t continue to respond to all the extra nitrogen from atmospheric pollution forever. Other factors, such as sunlight, or the availability of phosphorus and other important nutrients, will come into play and limit growth, restricting how much more carbon can be stored in vegetation. </p>
<p>To keep the land soaking up carbon this way, we’d need to continue releasing nitrogen into the atmosphere by burning fossil fuels and applying fertilisers to crops at the current rate. This isn’t a good solution. All that nitrogen seeps into waterways where it can deplete oxygen and kill aquatic wildlife. It also contributes to <a href="https://doi.org/10.1016/j.envpol.2021.117017">plant biodiversity loss</a>, as few plant species are adapted to cope with the extra nitrogen, which also increases the acidity of the soil.</p>
<p>Soil on arable farmland is still losing carbon, while gains in natural habitats are slowing. If these trends continue, the small net gain in carbon storage that we’ve observed across the UK since the 18th century could be reversed.</p>
<figure class="align-center ">
<img alt="Gnarled oak trees grow out of mossy boulders." src="https://images.theconversation.com/files/395459/original/file-20210416-19-oz8sj1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/395459/original/file-20210416-19-oz8sj1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/395459/original/file-20210416-19-oz8sj1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/395459/original/file-20210416-19-oz8sj1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/395459/original/file-20210416-19-oz8sj1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/395459/original/file-20210416-19-oz8sj1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/395459/original/file-20210416-19-oz8sj1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A recent report suggested that just 7% of the UK’s woodlands are in a good condition.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/ancient-gnarled-stunted-oak-tree-trunks-213662014">Helen Hotson/Shutterstock</a></span>
</figcaption>
</figure>
<p>Continuing to pollute just to maintain this thin advantage is not an option. But the news isn’t all bad. Changing the way people manage the land by reducing or preventing soil tillage, switching crops grown regularly and adding ones which can fix nitrogen like legumes and using manure-based fertilisers that add organic matter can <a href="https://www.4p1000.org/">sequester carbon in agricultural soils</a>.</p>
<p>Housing, food and energy production: the demands on the world’s land are high, but they’re particularly acute in a small country like the UK. Practices like <a href="https://theconversation.com/britain-needs-to-grow-more-trees-are-sheep-farms-the-answer-145872">rewilding</a> – where land ecosystems are allowed to naturally regenerate – can help permanently shift more carbon into the land without polluting the environment. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-crisis-the-countryside-could-be-our-greatest-ally-if-we-can-reform-farming-126304">Climate crisis: the countryside could be our greatest ally – if we can reform farming</a>
</strong>
</em>
</p>
<hr>
<p>The country has a long way to go to meet its 2050 net zero emissions target, but taking better care of the UK’s soil is a critical first step.</p><img src="https://counter.theconversation.com/content/158100/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jess Davies receives funding from UKRI, Defra and the EU Commission. </span></em></p><p class="fine-print"><em><span>Victoria Janes-Bassett does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Scientists need to know how much we can rely on the land to offset our emissions.Victoria Janes-Bassett, Senior Research Associate in Sustainable Land Management, Lancaster UniversityJess Davies, Chair Professor in Sustainability, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1566102021-03-10T14:13:56Z2021-03-10T14:13:56ZThe secret life of fungi: how they use ingenious strategies to forage underground<figure><img src="https://images.theconversation.com/files/388614/original/file-20210309-23-6ai9mt.png?ixlib=rb-1.1.0&rect=0%2C154%2C1051%2C928&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Three examples of the obstacle courses we tested our fungi within.</span> <span class="attribution"><span class="license">Author provided</span></span></figcaption></figure><p>When you think of fungi, you’ll probably picture a huddle of chubby brown mushrooms, or the large, red-capped toadstools you stumble across in the woods. In doing so, you’re reducing fungi to their reproductive organs – tasty or striking as they may often be.</p>
<p>The main body of a fungus is actually a large interwoven network called the <a href="https://www.asmscience.org/content/journal/microbiolspec/10.1128/microbiolspec.FUNK-0033-2017">mycelium</a>, which consists of incredibly thin fungal tubes called hyphae. These hyphae are a bit like plant roots: they grow into soil, unseen by us humans, on the hunt for nutrients. </p>
<p><a href="https://www.nature.com/articles/s41396-020-00886-7">Our recent research</a> used an artificial fungal obstacle course to spy on hyphal growth and behaviour. We found a remarkable variety of growth strategies employed by fungal hyphae – so many that we had to give them names.</p>
<p>From the brute force of the “zombie”, which breaks through physical barriers, to the intrepid “marathon runner”, who sets off way ahead of the pack to explore, fungal hyphae appear to be ingenious subterranean foragers. And our findings aren’t merely fascinating: they may have important implications for our fight against climate change, too.</p>
<h2>Foraging fungi</h2>
<p>Fungi are fascinating organisms. Neither plants nor animals, they belong to their own distinct kingdom, estimated to be composed of <a href="https://link.springer.com/article/10.1007/s13225-021-00472-y">between 2 and 6 million species</a>. And though they may look very different from us, fungi still – like us – have to find ways to locate food and solve problems in their environment.</p>
<p>Fungi are also crucial for all nutrient cycles. They decompose and recycle dead biomass in the environment, and help feed water and nutrients to the roots of about <a href="https://www.nature.com/articles/ncomms1046">90% of all land plants</a>. They can be a pain, too: they can cause diseases in humans, animals and plants, and <a href="https://www.nature.com/articles/nature10947">destroy huge amounts of</a> agricultural produce.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/complex-life-may-only-exist-because-of-millions-of-years-of-groundwork-by-ancient-fungi-117526">Complex life may only exist because of millions of years of groundwork by ancient fungi</a>
</strong>
</em>
</p>
<hr>
<p>Integral to fungi are the hyphae: tubes so thin that sometimes they’re not even visible to the naked eye. For reference, a human hair is about 50 micrometres wide, while fungal hyphae often are as thin as 2 or 3 micrometres. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/388601/original/file-20210309-15-pj5tpv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="One thick cylinder overlaid by one thinner one" src="https://images.theconversation.com/files/388601/original/file-20210309-15-pj5tpv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/388601/original/file-20210309-15-pj5tpv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=341&fit=crop&dpr=1 600w, https://images.theconversation.com/files/388601/original/file-20210309-15-pj5tpv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=341&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/388601/original/file-20210309-15-pj5tpv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=341&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/388601/original/file-20210309-15-pj5tpv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=429&fit=crop&dpr=1 754w, https://images.theconversation.com/files/388601/original/file-20210309-15-pj5tpv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=429&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/388601/original/file-20210309-15-pj5tpv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=429&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A 50 micrometre human hair intersected by a 6 micrometre filament. Hyphae are just 2 to 3 micrometres wide.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/w/index.php?curid=350295">Saperaud/wikicommons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Going underground</h2>
<p>Many fungi live most of their lives underground, out of sight. As such, we know very little about how these organisms experience their underground environment: if they have the ability to feel that there is food nearby, or what strategies they use to find it.</p>
<p>This was a challenge that we wanted to tackle. Together with biomedical engineers, we manufactured a transparent system of microscopic tunnels that allowed us to simulate the structures found in soil. These “soil chips” are effectively obstacle courses designed to put fungal hyphae through their paces on their search for food.</p>
<figure class="align-center ">
<img alt="A silver surface traversed by a line that is a fungal hyphae" src="https://images.theconversation.com/files/388606/original/file-20210309-13-1psjhj9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/388606/original/file-20210309-13-1psjhj9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/388606/original/file-20210309-13-1psjhj9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/388606/original/file-20210309-13-1psjhj9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/388606/original/file-20210309-13-1psjhj9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=471&fit=crop&dpr=1 754w, https://images.theconversation.com/files/388606/original/file-20210309-13-1psjhj9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=471&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/388606/original/file-20210309-13-1psjhj9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=471&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">One of our simplest ‘soil chip’ tests. The fungal hyphae, exploring from left to right, easily clears the obstacle.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In plant ecology, clonal plant roots are said to grow either like a phalanx unit (short and very densely) or a guerrilla army (far but sparsely). We were surprised to find this dichotomy unusable for our fungi: we needed many more categories. </p>
<p>So, we gave the fungi nicknames to reflect their different growth strategies. Some species had hyphae that grew dense but very far and very straight, without exploring their surroundings (“the marathon runner”). </p>
<p>Others progressed slowly but constantly for months, meandering past complicated turns and corners (“the snake”). Others still branched heavily, filled up almost all free spaces, and with incredible force broke themselves through solid parts of the chips (“the zombie”). </p>
<figure class="align-center ">
<img alt="A mess of lines on a silver background" src="https://images.theconversation.com/files/388613/original/file-20210309-17-1xk7e67.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/388613/original/file-20210309-17-1xk7e67.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=396&fit=crop&dpr=1 600w, https://images.theconversation.com/files/388613/original/file-20210309-17-1xk7e67.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=396&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/388613/original/file-20210309-17-1xk7e67.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=396&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/388613/original/file-20210309-17-1xk7e67.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=497&fit=crop&dpr=1 754w, https://images.theconversation.com/files/388613/original/file-20210309-17-1xk7e67.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=497&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/388613/original/file-20210309-17-1xk7e67.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=497&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In this example, ‘the zombie’ has brute-forced its way through our obstacle course.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Foraging strategies</h2>
<p>These distinct fungal strategies are probably evolutionary traits, given the diversity of environments that the different fungi might encounter. Dense growth strategies allow fungi to break down complex food sources that require large concentrated amounts of enzymes, while far-reaching exploration strategies help fungi to more quickly locate more ephemeral food sources that are spread out or far away.</p>
<p>We also found certain situations that gave fungi a hard time. For example, repeated sharp turns led some to get stuck in corners. Others lost their sense of direction after growing around a circular obstacle. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/388610/original/file-20210309-23-xfllkv.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A silver surface upon which a line is meandering into a corner" src="https://images.theconversation.com/files/388610/original/file-20210309-23-xfllkv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/388610/original/file-20210309-23-xfllkv.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=420&fit=crop&dpr=1 600w, https://images.theconversation.com/files/388610/original/file-20210309-23-xfllkv.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=420&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/388610/original/file-20210309-23-xfllkv.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=420&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/388610/original/file-20210309-23-xfllkv.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=527&fit=crop&dpr=1 754w, https://images.theconversation.com/files/388610/original/file-20210309-23-xfllkv.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=527&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/388610/original/file-20210309-23-xfllkv.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=527&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This hyphae, an example of ‘the snake’, has become trapped in a corner of our soil chip.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We were especially interested in those obstacles that hindered fungal growth. That’s because soils are the Earth’s largest terrestrial <a href="https://www.jswconline.org/content/73/6/145A">carbon reservoir</a>, and small changes in their carbon cycling could generate huge differences for <a href="https://ourworldindata.org/emissions-by-sector">atmospheric CO₂ levels</a>. Understanding how soil structures impact fungal growth may lead us to understand how to optimise soils for carbon sequestration – helping us store more CO₂ in the ground. </p>
<p>For now, we hope that our soil chips can continue to be used to spy on the secret life of fungi. Our study only looked at seven different litter-decomposing species of fungi, so there’s plenty of scope for new findings that could reveal how the foraging of fungi underground might affect ecosystems above it.</p><img src="https://counter.theconversation.com/content/156610/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span><a href="mailto:edith.hammer@biol.lu.se">edith.hammer@biol.lu.se</a> receives funding from the Swedish Research Council and the Swedish Foundation for Strategic Research. </span></em></p><p class="fine-print"><em><span><a href="mailto:kristin.aleklett.kadish@slu.se">kristin.aleklett.kadish@slu.se</a> has received funding from the Crafoord foundation during her postdoc at Lund University. </span></em></p>Using tiny ‘soil chips’, researchers have observed the forgaging strategies of fungi at a microscopic scale for the first time.Edith Hammer, Associate Lecturer, Department of Biology, Lund UniversityKristin Aleklett, Postdoctoral research fellow, Swedish University of Agricultural SciencesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1513642020-12-07T16:18:31Z2020-12-07T16:18:31ZPeatlands keep a lot of carbon out of Earth’s atmosphere, but that could end with warming and development<figure><img src="https://images.theconversation.com/files/373121/original/file-20201204-15-1j8bmae.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1024%2C768&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">More valuable than it looks.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/2i7ErG1">David Stanley/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p><a href="https://peatlands.org/peatlands/what-are-peatlands/">Peatlands</a> are a type of wetland where dead plant material doesn’t fully decompose because it’s too soggy. In these ecosystems, peat builds up as spongy dark soil that’s sometimes referred to as sod or turf. Over thousands of years, yards-thick layers of <a href="https://en.wikipedia.org/wiki/Peat">peat</a> accumulate and trap huge amounts of carbon, helping to cool the climate on a global scale. </p>
<p>But that might not be true for much longer. Warming temperatures and human actions, such as draining bogs and converting them for agriculture, threaten to turn the world’s peatlands from carbon reservoirs to carbon sources.</p>
<p>In a <a href="https://www.nature.com/articles/s41558-020-00944-0#citeas">newly published study</a>, our <a href="http://pastglobalchanges.org/science/wg/peat-carbon/intro">multidisciplinary team of 70 scientists</a> from around the world analyzed existing research and surveyed 44 leading experts to identify factors that could change peatlands’ carbon balance now and in the future. We found that permafrost degradation, warming temperatures, rising sea levels and drought are causing many peatlands around the world to lose some of their stored carbon. This is in addition to rapid degradation caused by human activity. And unless steps are taken to protect peatlands, carbon loss could accelerate.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/373119/original/file-20201204-21-16ozcjc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map showing global distribution of peatlands." src="https://images.theconversation.com/files/373119/original/file-20201204-21-16ozcjc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/373119/original/file-20201204-21-16ozcjc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=359&fit=crop&dpr=1 600w, https://images.theconversation.com/files/373119/original/file-20201204-21-16ozcjc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=359&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/373119/original/file-20201204-21-16ozcjc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=359&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/373119/original/file-20201204-21-16ozcjc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=451&fit=crop&dpr=1 754w, https://images.theconversation.com/files/373119/original/file-20201204-21-16ozcjc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=451&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/373119/original/file-20201204-21-16ozcjc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=451&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Peatlands are found in an estimated 180 countries. Many of them have not been recognized and are not yet properly mapped.</span>
<span class="attribution"><a class="source" href="https://farm5.staticflickr.com/4575/38989454502_ccb67be1e8_b.jpg">Levi Westerveld/GRID-Arendal</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>From carbon sink to carbon source</h2>
<p>Although they only occupy 3% of the global land area, peatlands contain about 25% of global soil carbon — twice as much as the world’s forests. Peatlands exist on every continent, even in <a href="https://doi.org/10.1038/s41598-017-12479-0">Antarctica</a>. In the U.S. they are found in many states, including Maine, Pennsylvania, Washington and Wisconsin. These ecosystems form where partially decayed organic matter accumulates in cold soil that is nearly always wet, which <a href="https://www.livescience.com/38983-irish-bog-body.html">dramatically slows decomposition</a>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/sMawMMtME7g?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Humans have used peat for centuries as a fuel, and also to flavor whiskey.</span></figcaption>
</figure>
<p>But now climate change is altering those conditions. For example, in many regions of the Arctic, <a href="https://doi.org/10.1038/d41586-019-01313-4">rapid permafrost thawing</a> promotes microbial activity that releases greenhouse gases into the atmosphere. These microbes feed off carbon-rich peats that were once frozen. </p>
<p>Massive peatland fires also contribute. Recent wildfires <a href="https://www.themoscowtimes.com/2020/05/29/zombie-wildfires-threaten-arctic-russia-scientists-warn-a70416">like those in Russia</a> are known to release as much carbon in a few months as total human carbon dioxide emissions in an entire year. And these fires are especially tricky to put out. Embers within the dense organic matter can reignite many months or even years later.</p>
<p>Human activities are also increasing greenhouse gas releases from these carbon-rich ecosystems. In the United Kingdom, for example, <a href="https://candidegardening.com/GB/stories/ea083986-c223-44f9-a50f-1ff2813cdf09">extracting peat for use in gardening</a> has caused peatlands to emit an estimated 16 million tons of carbon every year – roughly equivalent to the annual greenhouse gas emissions from <a href="https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator">over 12 million cars</a>. </p>
<p>In <a href="https://news.mongabay.com/2020/06/as-fires-strangle-national-parks-indonesia-struggles-to-restore-peatlands/">Indonesia</a> and <a href="https://www.thestar.com.my/lifestyle/living/2020/11/24/ways-to-save-degraded-peatlands-and-stop-them-turning-into-fire-hazards">Malaysia</a>, as fertile land becomes increasingly scarce, peatlands are being burned, drained, and repurposed. Already, most peatlands in Indonesia have been <a href="https://edition.cnn.com/interactive/2019/11/asia/borneo-climate-bomb-intl-hnk/">destroyed in order to build palm oil plantations</a>. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/373118/original/file-20201204-19-14drpop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Peat blocks stacked to dry" src="https://images.theconversation.com/files/373118/original/file-20201204-19-14drpop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/373118/original/file-20201204-19-14drpop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=598&fit=crop&dpr=1 600w, https://images.theconversation.com/files/373118/original/file-20201204-19-14drpop.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=598&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/373118/original/file-20201204-19-14drpop.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=598&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/373118/original/file-20201204-19-14drpop.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=751&fit=crop&dpr=1 754w, https://images.theconversation.com/files/373118/original/file-20201204-19-14drpop.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=751&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/373118/original/file-20201204-19-14drpop.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=751&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Peat cut into blocks and drying on racks in Tierra del Fuego, Argentina.</span>
<span class="attribution"><span class="source">Julie Loisel</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>The <a href="https://www.wri.org/blog/2016/04/destruction-tropical-peatland-overlooked-source-emissions">World Resources Institute</a> estimates that in Indonesia and Malaysia, peatland draining results in total annual emissions equal to those of nearly 70 coal plants. These activities also endanger vulnerable animal populations, such as orangutans and various species of freshwater fish. Peatland degradation due to human activity accounts for <a href="https://doi.org/10.1038/s41558-019-0615-5">5-10% of annual carbon dioxide emissions from human activity</a>, despite these zones’ tiny geographic footprint. </p>
<h2>Quantifying peatland carbon</h2>
<p>Predicting how much carbon will be released from peatlands worldwide is hard to do, especially because no models can adequately represent these ecosystems and the many factors that influence their carbon balance. </p>
<p>Peatlands are not included in most <a href="https://www.climateurope.eu/earth-system-modeling-a-definition/">earth system models</a> that scientists use to make future climate change projections. There is a long-held view that peatlands are minor players in the global carbon cycle on a <a href="https://doi.org/10.1038/s41558-018-0271-1">year-to-year basis</a>, but our study and <a href="https://doi.org/10.1038/s41561-019-0462-z">many others</a> show that climate change and human intervention are making these ecosystems very dynamic. Our study highlights the need to integrate peatlands into these models; we also hope it can help direct new research. </p>
<p>Even though models are not ready, decisions need to be made now about how to manage peatlands. That’s why we surveyed experts as a first step towards predicting the fate of peat carbon worldwide. </p>
<p>Based on their responses, we estimate that 100 billion tons of carbon could be emitted from peatlands by 2100 – an amount equivalent to about 10 years of emissions from all human activities, including burning fossil fuels and clearing forests. The experts we consulted have not reached a consensus, and our estimate is highly uncertain: Net changes in peat carbon over the next 80 years could range from a gain of 103 billion tons to a loss of 360 billion tons. </p>
<p>Not every region will be affected the same way. High-latitude peatlands might see an increase in carbon storage under a warming climate because of increased plant growth and greater peat accumulation. Tropical peats, on the other hand, are more likely to dry out and burn due to warming temperatures and human activity. These factors and human choices about peatland use will affect whether these areas become carbon sources or sinks in the future.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/373120/original/file-20201204-17-134iqgm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Tropical forested wetland" src="https://images.theconversation.com/files/373120/original/file-20201204-17-134iqgm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/373120/original/file-20201204-17-134iqgm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=601&fit=crop&dpr=1 600w, https://images.theconversation.com/files/373120/original/file-20201204-17-134iqgm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=601&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/373120/original/file-20201204-17-134iqgm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=601&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/373120/original/file-20201204-17-134iqgm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=755&fit=crop&dpr=1 754w, https://images.theconversation.com/files/373120/original/file-20201204-17-134iqgm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=755&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/373120/original/file-20201204-17-134iqgm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=755&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Tropical peatlands in Panama.</span>
<span class="attribution"><span class="source">Angela Gallego-Sala</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Overall, our results suggest that carbon releases will surpass carbon gains in the coming years, primarily because of human impacts in tropical peatlands. This switch from carbon sink to carbon source will feed a <a href="https://sciencetrends.com/positive-feedback-loop-examples/">positive feedback loop</a>, with peatlands releasing carbon that makes Earth’s climate warmer, which makes peatlands release more carbon, and so on.</p>
<p>Despite the uncertainty in our findings, we believe our results show that peatlands should be included in climate models, and that nations should take steps to preserve them. </p>
<h2>Toward sustainable use</h2>
<p>A balance must be achieved between wise peatland use and local economic needs. Given how much carbon peatlands hold and how vulnerable they are, many surveyed experts believe people soon will adopt more sustainable practices for managing them. But others are not so optimistic. In regions such as <a href="https://truthout.org/articles/its-not-just-the-amazon-we-must-also-protect-congo-basin-peatlands-from-fire/">the Amazon and the Congo basins</a>, where <a href="https://doi.org/10.1007/s11027-017-9774-8">large peatland complexes</a> were <a href="https://doi.org/10.1088/1748-9326/9/12/124017">recently discovered</a>, it is critical to take action to preserve them.</p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p>Peatlands should also be considered in <a href="https://climateanalytics.org/publications/2018/integrated-assessment-models-what-are-they-and-how-do-they-arrive-at-their-conclusions/">integrated assessment models</a> that researchers use to understand climate change impacts and options for mitigating them. Models that project future socioeconomic change and carbon emission pathways could help develop incentives such as peatland carbon pricing and sustainable use practices. This would change the way these ecosystems are valued and managed. </p>
<p>The first step, however, is to raise awareness around the world of this precious natural resource and the consequences of continuing to exploit it.</p><img src="https://counter.theconversation.com/content/151364/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julie Loisel receives funding from the US National Science Foundation and the National Geographic Society. </span></em></p>Peat beds around the world hold huge quantities of carbon and keep it from warming the planet. But rising temperatures and over-use could turn them from a brake on climate change into an accelerant.Julie Loisel, Assistant Professor of Geography, Texas A&M UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1500542020-11-17T05:22:13Z2020-11-17T05:22:13ZClimate Explained: what would happen if we cut down the Amazon rainforest?<figure><img src="https://images.theconversation.com/files/369707/original/file-20201117-15-1pr0bsu.jpg?ixlib=rb-1.1.0&rect=16%2C98%2C5439%2C3459&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Gustavo Frazao</span></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/287622/original/file-20190811-144878-bvgm9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/287622/original/file-20190811-144878-bvgm9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/287622/original/file-20190811-144878-bvgm9l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/287622/original/file-20190811-144878-bvgm9l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/287622/original/file-20190811-144878-bvgm9l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/287622/original/file-20190811-144878-bvgm9l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/287622/original/file-20190811-144878-bvgm9l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em><strong><a href="https://theconversation.com/nz/topics/climate-explained-74664">Climate Explained</a></strong> is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.</em> </p>
<p><em>If you have a question you’d like an expert to answer, please send it to <a href="mailto:climate.change@stuff.co.nz">climate.change@stuff.co.nz</a></em></p>
<hr>
<blockquote>
<p><strong>What would happen if we cut down the entire Amazon rainforest? Could it be replaced by an equal amount of reforestation elsewhere?</strong></p>
</blockquote>
<p>Removing the entire Amazon rainforest would have myriad consequences, with the most obvious ones possibly not the worst. </p>
<p>Most people will first think of the carbon currently stored in the Amazon, the world’s largest rainforest. But the consequences would be far-reaching for the climate as well as biodiversity and ecosystems — and, ultimately, people. </p>
<p>The overall impact of the Amazon’s complete removal is unthinkable and beyond the power of our current predictive tools. But let’s look at some aspects we can describe.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/statistic-of-the-decade-the-massive-deforestation-of-the-amazon-128307">Statistic of the decade: The massive deforestation of the Amazon</a>
</strong>
</em>
</p>
<hr>
<h2>Storing carbon, distributing water</h2>
<p>The Amazon rainforest is estimated to harbour about <a href="https://iopscience.iop.org/article/10.1088/1748-9326/aabc61/meta">76 billion tonnes of carbon</a>. If all trees were cut down and burned, the forest’s carbon storage capacity would be lost to the atmosphere. </p>
<p>Some of this carbon would be taken up by the oceans, and some by other ecosystems (such as temperate or arctic forests), but no doubt this would exacerbate climate warming. For comparison, humans emit about 10 billion tonnes of carbon every year through the <a href="https://ueaeprints.uea.ac.uk/id/eprint/69293/">burning of fossil fuels</a>.</p>
<p>But the Amazon forest does more than store carbon. It is also responsible for the circulation of huge quantities of water. </p>
<figure class="align-center ">
<img alt="Clouds over the Amazon rainforest." src="https://images.theconversation.com/files/369682/original/file-20201116-23-f8e6tx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/369682/original/file-20201116-23-f8e6tx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=771&fit=crop&dpr=1 600w, https://images.theconversation.com/files/369682/original/file-20201116-23-f8e6tx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=771&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/369682/original/file-20201116-23-f8e6tx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=771&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/369682/original/file-20201116-23-f8e6tx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=969&fit=crop&dpr=1 754w, https://images.theconversation.com/files/369682/original/file-20201116-23-f8e6tx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=969&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/369682/original/file-20201116-23-f8e6tx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=969&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A uniform layer of tiny ‘popcorn’ clouds covers the Amazon rainforest during the dry season.</span>
<span class="attribution"><span class="source">NASA/Jeff Schmaltz</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>This image, captured by NASA’s Aqua satellite in 2009, shows how the forest and the atmosphere interact to create a uniform layer of “popcorn” clouds during the dry season. It is during this period, the time without rain, that the <a href="https://earthobservatory.nasa.gov/images/39936/afternoon-clouds-over-the-amazon-rainforest">forest grows the most</a>. </p>
<p>If the Amazon’s cloud systems and its capacity to recycle water were to be disrupted, the ecosystem would tip over and irreversibly <a href="https://www.nature.com/articles/d41586-019-03595-0#ref-CR8">turn into dry savannah</a> very quickly. Estimates of where this tipping point could lie range from 40% deforestation to just <a href="https://advances.sciencemag.org/content/5/12/eaba2949?intcmp=trendmd-adv">20% loss of forest cover</a> from the Amazon. </p>
<p>Reforestation elsewhere to achieve the same amount of carbon storage is technically possible, but we have neither the time (several hundred years would be needed) nor the land (at least an equivalent surface area would be required). </p>
<p>Another reason why reforestation is not a remedy is that the water the rainforest circulates — and with it the availability of nutrients — would disappear. </p>
<p>Once you cut the circulation of water through (partial) deforestation, there is a point of no return. The water doesn’t disappear from the planet, but certainly from the forest ecosystems, with immediate and powerful <a href="https://www.nature.com/articles/d41586-019-03595-0?fbclid=IwAR0axCO7TmkJ34bprB2948XqNQUXPr8tMX4VZjz4AC6dm_f7uvH37hUSMQo">consequences for the world’s climate</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/we-found-2-c-of-warming-will-push-most-tropical-rainforests-above-their-safe-heat-threshold-139071">We found 2˚C of warming will push most tropical rainforests above their safe 'heat threshold'</a>
</strong>
</em>
</p>
<hr>
<h2>Loss of life</h2>
<p>Perhaps the most drastic, and least reversible, impact would be the loss of wildlife diversity. </p>
<p>The Amazon hosts an estimated <a href="https://www.pnas.org/content/105/Supplement_1/11498">50,000 plant species</a> — although more recent estimates cite a <a href="https://www.pnas.org/content/114/40/10695">slightly lower number</a>. </p>
<p>The number of animal species found in the Amazon is even higher, with the largest part made up by insects, representing around <a href="http://periodicos.uefs.br/ojs/index.php/sociobiology/article/view/4061">10% of the known insect fauna</a>, as well as a large but unknown number of fungi and microbes. </p>
<p>Once species are lost, they are lost forever, and this would ultimately be the most harmful consequence of cutting down the Amazon. It would possibly be worse than the loss of its role as a massive redistributor and storage of water and carbon.</p>
<p>Last but certainly not least, there are about <a href="https://wwf.panda.org/knowledge_hub/where_we_work/amazon/about_the_amazon/">30 million people</a> living in and near the Amazon rainforest. </p>
<p>The consequences of losing the forest as a provider of the ecosystem services mentioned above and as a source of food and habitat are unfathomable. The repercussions would reach far into global politics, the global economy, and societal issues.</p><img src="https://counter.theconversation.com/content/150054/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sebastian Leuzinger receives funding from The Royal Society of New Zealand. </span></em></p>As the world’s largest rainforest, the Amazon is not only an important carbon sink, but also home to thousands of species of plants and animals and a crucial part of the water cycle.Sebastian Leuzinger, Professor, Auckland University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1435512020-08-05T11:53:33Z2020-08-05T11:53:33ZWind farms built on carbon-rich peat bogs lose their ability to fight climate change<figure><img src="https://images.theconversation.com/files/351267/original/file-20200805-22-keu8o9.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5184%2C3453&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Chico & Clough</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Wind power in the UK <a href="https://www.gov.uk/government/statistics/energy-trends-section-6-renewables">now accounts for nearly 30%</a> of all electricity production. Land-based wind turbines now produce the cheapest type of energy – and there is no doubt wind farms can help to reduce greenhouse gas emissions by replacing the fossil fuels that have traditionally been used to generate electricity.</p>
<p>But what of wind turbines built on top of sensitive, natural environments – does low-carbon energy still help reduce emissions if it involves disturbing the kinds of habitats that are effective at trapping carbon and keeping it out of the atmosphere? This is an important question, but it is one that is too rarely being asked.</p>
<p><a href="https://onlinelibrary.wiley.com/doi/10.1002/esp.4927">In our recent study</a>, we found that wind farms in Spain are being built on rare peat bogs that store vast quantities of planet-warming carbon. Because these habitats are so poorly mapped, there’s a good chance that this mistake is being replicated in many other places throughout Europe, including the UK.</p>
<h2>Europe’s unmapped peatlands in peril</h2>
<p>Peatlands are a natural carbon sink and, despite <a href="https://www.sciencedirect.com/science/article/abs/pii/S0341816217303004">covering less than 3%</a> of the Earth’s land surface, they <a href="https://esajournals.onlinelibrary.wiley.com/doi/10.2307/1941811">contain 20% of all the carbon stored in soils worldwide</a>. </p>
<p>Because some peatlands aren’t mapped, they <a href="http://mires-and-peat.net/pages/volumes/map24/map2402.php">have often been ignored</a>, despite their important role in slowing climate change. Blanket bogs are a rare and unique type of peatland that cover entire landscapes with a distinctive vegetation, often composed of cotton grass, heather, and Sphagnum mosses, which is <a href="https://www.newscientist.com/article/dn22313-scattering-moss-can-restore-key-carbon-sink/">a particularly effective species</a> for locking up carbon. </p>
<figure class="align-center ">
<img alt="A clump of white cottongrass." src="https://images.theconversation.com/files/351266/original/file-20200805-18-oqdq8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/351266/original/file-20200805-18-oqdq8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/351266/original/file-20200805-18-oqdq8b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/351266/original/file-20200805-18-oqdq8b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/351266/original/file-20200805-18-oqdq8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/351266/original/file-20200805-18-oqdq8b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/351266/original/file-20200805-18-oqdq8b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Blanket bogs can often be recognised by their white cottongrass.</span>
<span class="attribution"><span class="source">Chico & Clough</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In the UK and Ireland, blanket bogs cover great expanses and are a key part of the landscape in <a href="https://www.theflowcountry.org.uk/">Flow Country</a>, a region of the north of Scotland, and in the north and south Pennines in England. In France or Spain, <a href="https://www.schweizerbart.de/publications/detail/isbn/9783510653836/Joosten_Tanneberger_Moen_Mires_and_peat">this habitat is rare</a>, but <a href="https://onlinelibrary.wiley.com/doi/10.1002/esp.4927">our research</a> uncovered 14 unrecorded and unprotected blanket bogs in northern Spain that represent the southernmost <a href="https://onlinelibrary.wiley.com/doi/10.1002/esp.4927">edge of this habitat’s range in Europe</a>.</p>
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Read more:
<a href="https://theconversation.com/bogs-are-unique-records-of-history-heres-why-100627">Bogs are unique records of history – here's why</a>
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<p>Peatlands – and in particular blanket bogs – <a href="https://www.schweizerbart.de/publications/detail/isbn/9783510653836/Joosten_Tanneberger_Moen_Mires_and_peat">face a number of pressures</a> across Europe. Overgrazing, drainage to plant crops and commercial forest, burning to improve grazing and support field sports and, more recently, wind farm developments, can change the natural function of peatlands so that they switch from slowing climate change as carbon sinks, to become carbon sources that leach greenhouse gases to the atmosphere. </p>
<p>Although peat is naturally eroded by wind, rain and ice, blanket bogs grazed by livestock can lose <a href="http://mires-and-peat.net/pages/volumes/map24/map2414.php">four to six</a> times more carbon than protected bogs. But the most serious risk to these habitats today is wind farms. Unprotected blanket bogs often cover mountain peaks, where there is also great potential for generating wind energy. During wind farm construction, vegetation that helps to trap the carbon is removed to create turbine bases and vehicle access tracks. These tracks create artificial streams that drain the peat and reshape the terrain. </p>
<figure class="align-center ">
<img alt="The author stood on a road next to a bank of excavated peat and two wind turbines." src="https://images.theconversation.com/files/349913/original/file-20200728-27-mxx5f8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/349913/original/file-20200728-27-mxx5f8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/349913/original/file-20200728-27-mxx5f8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/349913/original/file-20200728-27-mxx5f8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/349913/original/file-20200728-27-mxx5f8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/349913/original/file-20200728-27-mxx5f8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/349913/original/file-20200728-27-mxx5f8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Creating tracks on peatlands can break the bog up, causing the peat to dry out and release carbon emissions.</span>
<span class="attribution"><span class="source">Chico & Clough</span>, <span class="license">Author provided</span></span>
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<p>Recent research has shown that the drainage caused by building and maintaining <a href="https://www.sciencedirect.com/science/article/abs/pii/S0195925517303815">wind turbines</a> can affect the whole peatland, not just the area next to the farm and its tracks. <a href="https://onlinelibrary.wiley.com/doi/10.1002/esp.4927">In our research</a>, we encountered a track that divided the largest unrecognised blanket bog we found in the Cantabrian Mountains into two separate peatlands. The rupture is draining the bog and likely releasing carbon as the peat dries and breaks down.</p>
<p>This release can be so significant that the climate benefit of generating clean energy is <a href="https://www.sciencedirect.com/science/article/abs/pii/S0301421513010896">likely to be neutralised</a>. For bogs on the <a href="https://onlinelibrary.wiley.com/doi/10.1002/esp.4927">southernmost edge of their range</a> in Europe, wind farm construction could mean the total destruction of this habitat and the loss of a natural way of fighting climate change. </p>
<p>In spite of their current degraded state, restoring and protecting blanket bogs could <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14449">reverse the situation</a> and restore the capability of these habitats as <a href="https://www.youtube.com/watch?time_continue=3&v=GlfW7aYouYQ&feature=emb_logo">climate allies</a>.</p>
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<img alt="The author stood on a large bank of excavated peat." src="https://images.theconversation.com/files/349911/original/file-20200728-25-i30crs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/349911/original/file-20200728-25-i30crs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/349911/original/file-20200728-25-i30crs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/349911/original/file-20200728-25-i30crs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/349911/original/file-20200728-25-i30crs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/349911/original/file-20200728-25-i30crs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/349911/original/file-20200728-25-i30crs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Peatlands are poorly mapped throughout Europe, but they are vital for slowing climate change.</span>
<span class="attribution"><span class="source">Chico & Clough</span>, <span class="license">Author provided</span></span>
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<p>We need to map all currently undiscovered peatlands and protect them under <a href="https://theconversation.com/eu-wildlife-laws-should-be-celebrated-and-retained-not-treated-as-red-tape-75407">the EU’s Habitats Directive</a>. Restoring degraded peatlands and reducing human pressures on them could help them recover their natural abilities for storing carbon. In the UK, the research partnership <a href="https://www.moorsforthefuture.org.uk/">Moors for the Future</a> is attempting to restore substantial areas of degraded blanket bog by covering areas of bare peat with vegetation such as Sphagnum mosses and blocking streams to reduce drainage.</p>
<p>Wind farms are a great way to generate clean energy, but where they are built needs careful consideration. It is perhaps ironic that one of our best man-made tools for fighting climate change can become one of our most unhelpful if it interferes with another natural solution to the problem.</p><img src="https://counter.theconversation.com/content/143551/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Guaduneth Chico receives funding from British Society for Geomorphology and Bizkaia Provincial Council</span></em></p><p class="fine-print"><em><span>Ben Clutterbuck receives funding from Bizkaia Provincial Council, National Trust, Natural England, Moors for the Future Partnership and Yorkshire Water Plc.</span></em></p><p class="fine-print"><em><span>Nicholas Midgley does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We discovered wind farms in Spain that had carved up peat bogs, causing them to release carbon to the atmosphere.Guaduneth Chico, Lecturer in Environmental Sciences and GIS, Nottingham Trent UniversityBen Clutterbuck, Senior Lecturer in Environmental Science, Nottingham Trent UniversityNicholas Midgley, Lecturer in Physical Geography, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.