tag:theconversation.com,2011:/fr/topics/desertification-19970/articlesdesertification – The Conversation2023-11-26T08:40:39Ztag:theconversation.com,2011:article/2170672023-11-26T08:40:39Z2023-11-26T08:40:39ZClimate adaptation funds are not reaching frontline communities: what needs to be done about it<p>Communities around the world face <a href="https://public.wmo.int/en/our-mandate/climate/wmo-statement-state-of-global-climate/Africa-2022">increasingly severe</a> and <a href="https://www.globalcitizen.org/en/content/facts-about-climate-change-in-africa/">frequent impacts</a> from climate change. They are on the “frontlines” of droughts, flooding, desertification and sea level rise. </p>
<p>International climate finance is supposed to help. In the 2015 Paris Agreement, the world’s wealthiest countries pledged <a href="https://unfccc.int/process-and-meetings/the-paris-agreement/the-glasgow-climate-pact/cop26-outcomes-finance-for-climate-adaptation#Developed-countries-have-pledged-USD-100-billion-a">US$50 billion annually</a> to support climate adaptation among those “particularly vulnerable” to climate change. Climate adaptation is the adjustments humans make to reduce exposure to climate risk. </p>
<p>Eight years later, it is clear that this money is failing to reach vulnerable “frontline communities”, especially in sub-Saharan Africa. Recently, Mozambique, Zimbabwe, Malawi, South Sudan and Niger have been among the <a href="https://www.germanwatch.org/sites/germanwatch.org/files/2021-01/cri-2021_table_10_most_affected_countries_in_2019.jpg">top ten most affected countries</a>.</p>
<p>The host country of the upcoming annual United Nations climate negotiations (COP28), the United Arab Emirates, has announced it is focused on “<a href="https://www.cop28.com/en/news/2023/10/cop28-presidency-co-hosts-global-dialogue-in-abu-dhabi-to-focus-on-accelerating-the-energy">fixing climate finance</a>”. </p>
<p>I am a researcher who has studied international climate finance for seven years, both at the annual COPs and through research in <a href="https://www.sei.org/about-sei/press-room/finance-for-climate-adaptation-fails-reach-most-vulnerable/">Madagascar</a>, Mauritius and <a href="https://www.sei.org/projects/equity-in-adaptation-finance/">Namibia</a>. My work explores how to make climate finance more equitable and accessible for vulnerable communities.</p>
<p>It’s my view that the countries that contribute the bulk of the funding for climate adaptation can ensure more money reaches those who need it most. To do that they must first understand why financing isn’t reaching frontline communities. Otherwise money will continue to fall well short of need.</p>
<h2>Why funding isn’t reaching vulnerable communities</h2>
<p>The clearest reason why adaptation finance does not reach these communities is that there is simply not enough of it. Wealthy countries have <a href="https://www.theguardian.com/environment/2021/sep/20/rich-countries-not-providing-poor-with-pledged-climate-finance-analysis-says">consistently failed</a> to deliver on the US$50 billion commitment. Every year the gap between needs and support grows. The latest <a href="https://www.unep.org/resources/adaptation-gap-report-2023">Adaptation Gap Report</a> estimates that international adaptation finance is 10-18 times below need.</p>
<p>Beyond this shortfall, the current structure of climate finance prevents frontline communities from accessing support. <a href="https://www.sciencedirect.com/science/article/pii/S0959378022000139">Studies show</a> that the poorest and most vulnerable countries receive less than their fair share of adaptation finance. Support for sub-Saharan African countries is <a href="https://theconversation.com/five-ways-in-which-finance-for-climate-adaptation-in-africa-falls-short-169280">as little as US$5 per person</a> per year. </p>
<p>Two key barriers explain this disconnect. The first is the overlap of climate vulnerability with conflict and political instability. <a href="https://www.icrc.org/sites/default/files/topic/file_plus_list/rain_turns_to_dust_climate_change_conflict.pdf#page=12">Twelve of the 20 countries</a> most vulnerable to climate change are also affected by conflict. Vulnerable countries are also prone to political turmoil, frequent changes in government, and high levels of government corruption.</p>
<p>UN climate funds and other major funders like the World Bank see these countries as less “ready” for adaptation projects. <a href="https://deepblue.lib.umich.edu/handle/2027.42/169654">My research</a> has also found that wealthy countries worry their taxpayers’ money will be lost to corruption.</p>
<p>The second barrier is the finance application process. Proposals for UN climate funds, such as the <a href="https://www.wri.org/research/improving-access-green-climate-fund-how-fund-can-better-support-developing-country">Green Climate Fund</a>, can number hundreds of pages. Application requirements differ from fund to fund. It can take years to develop a proposal and to receive the money.</p>
<h2>Reaching frontline communities</h2>
<p>Even when vulnerable countries receive international support, further barriers can prevent it from reaching frontline communities. Currently, only <a href="https://www.carbonbrief.org/guest-post-three-major-gaps-in-climate-adaptation-finance-for-developing-countries/">17% of adaptation finance has reached local levels</a>. My research in <a href="https://deepblue.lib.umich.edu/handle/2027.42/169654">Madagascar and Mauritius</a> found both administrative and political barriers.</p>
<p>National governments consume resources administering grants, often hiring expensive foreign consultants to plan, implement and monitor projects. These costs eat into the money intended for local communities. The focus on large, individual projects tends to concentrate funding in one area, limiting how far benefits can reach.</p>
<p>Funds also require clear evidence of success. Governments might invest in projects they know will succeed rather than take innovative approaches or choose riskier areas. </p>
<p>National governments also make decisions for political reasons. They tend to distribute resources – including money for adaptation – based on what will help them stay in power. They are more likely to fund political supporters than opponents. Communities are often vulnerable precisely because they are politically marginalised.</p>
<p>Finally, studies show that adaptation finance, like development funding, can be lost to corruption and mismanagement. Wealthy and powerful elites can <a href="https://theecologist.org/2021/jan/22/adaptation-funds-increase-climate-vulnerability">“capture” the benefits</a> of internationally financed projects, such as a <a href="https://journals.plos.org/climate/article?id=10.1371/journal.pclm.0000050">disproportionate share of rice seeds</a> for a project to build the resilience of agriculture in Madagascar.</p>
<h2>How to fix it</h2>
<p>It is not too late to change how adaptation finance flows to ensure more of it reaches vulnerable communities. The first step is to increase funding for adaptation. Support for adaptation <a href="https://www.unep.org/resources/adaptation-gap-report-2023">actually declined in 2021</a>, the most recent year for which we have data. Wealthy countries must meet the commitments they made in the Paris Agreement.</p>
<p>The second step is for UN funds, the World Bank and wealthy countries to dedicate a greater proportion of funding to the most vulnerable countries. They must do so regardless of whether these countries are affected by conflict, instability and corruption.</p>
<p>For UN funds this can be accomplished by simplifying and standardising application procedures. Funds can also dedicate more resources to help countries prepare proposals. They should focus less on demanding clear results and more on supporting adaptation that aligns with national and local priorities.</p>
<p>Wealthy countries that contribute to climate funds need to give up some power over the money. They will have to accept imperfect governance and that some funding will be lost to mismanagement and corruption. They have tolerated such trade-offs before, such as during the <a href="https://www.weforum.org/agenda/2020/07/corruption-covid-19-how-to-fight-back/">COVID pandemic</a>, when urgency outweighed concerns over waste and fraud.</p>
<p>But funders should also push for increased transparency around projects. They can encourage scrutiny by local civil society groups, for example, by publishing project information in local languages.</p>
<p>The third step is to experiment. For example, the Green Climate Fund is currently experimenting with <a href="https://www.greenclimate.fund/project/fp024">“decentralised” adaptation finance</a> in Namibia. Rather than a single large project, the Namibian government broke the funds into 31 small grants for community-based organisations. Together with the University of Namibia, we are <a href="https://www.sei.org/projects/equity-in-adaptation-finance/">examining whether and how</a> this approach helps more funding reach frontline communities. Early results are encouraging.</p>
<p>Fixing climate finance is not simple, but it is urgent. Failing to do so means leaving the most vulnerable alone to face the increasing threats of climate change.</p><img src="https://counter.theconversation.com/content/217067/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Katherine Browne has received funding from the US Department of Education (Fulbright-Hayes Doctoral Dissertation Abroad fellowship), US State Department (Fulbright Fellowship), the University of Michigan, and Swedish Research Council for Sustainable Development (FORMAS).</span></em></p>Getting climate funds to frontline communities may require rich countries and the UN easing control over how the money is spent.Katherine Browne, Research Fellow, Stockholm Environment InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2129792023-09-26T13:44:03Z2023-09-26T13:44:03ZEnvironmental disasters and climate change force people to cross borders, but they’re not recognised as refugees – they should be<p>As our planet warms, we’re experiencing <a href="https://www.c2es.org/content/extreme-weather-and-climate-change/">more frequent</a> and severe weather events, rising sea levels, prolonged droughts and altered ecosystems. These environmental shifts directly affect people’s livelihoods by destroying crops and depleting water sources. They make once-inhabitable areas uninhabitable. </p>
<p>In response to these challenges, many individuals and communities have no choice but to abandon their homes and seek safety elsewhere. The vast majority will remain within their country borders – it’s predicted that by 2050 up to <a href="https://www.worldbank.org/en/news/press-release/2021/10/27/climate-change-could-further-impact-africa-s-recovery-pushing-86-million-africans-to-migrate-within-their-own-countries">86 million Africans</a> will migrate within their own countries due to weather shocks. But some will cross borders, triggering the need for international protection. </p>
<p>The challenge, however, is that people crossing borders due to weather don’t qualify as refugees under key laws and conventions. This displacement could be due to sudden-onset events, such as volcanic eruptions or flooding, which may pose an immediate threat to life. Or it could be due to slow-onset events, such as desertification or rising sea levels, which may eventually make life untenable. </p>
<p>It’s hard to say exactly how many people this affects because it’s a <a href="https://www.un.org/sustainabledevelopment/blog/2019/06/lets-talk-about-climate-migrants-not-climate-refugees/">complex topic</a>. However, we do know that cross-border migration affects <a href="https://www.savethechildren.net/news/drought-and-conflict-drive-highest-number-somalis-kenya-refugee-camps-decade">tens of thousands of people</a> every year. For instance <a href="https://www.unhcr.org/news/horn-africa-drought-enters-sixth-failed-rainy-season-unhcr-calls-urgent-assistance">drought conditions</a> in 2022, exacerbated by political insecurity and instability, forced at least 180,000 refugees from Somalia and South Sudan into parts of Kenya and Ethiopia.</p>
<p>It’s <a href="https://www.researchgate.net/publication/367965451_African_Shifts_The_Africa_Climate_Mobility_Report_Addressing_Climate-Forced_Migration_Displacement#page=85">predicted</a> that the number of people displaced due to weather shifts or disasters will reach as many as 1.2 million people by 2050. This figure will depend on how changes in the climate unfold. </p>
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Read more:
<a href="https://theconversation.com/climate-change-will-force-up-to-113m-people-to-relocate-within-africa-by-2050-new-report-193633">Climate change will force up to 113m people to relocate within Africa by 2050 - new report</a>
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<p>Without refugee status, those forced to move across borders due to weather events may not receive valuable support. Depending on the individual country, support can include the right to live and work, access to health or education services and the right to move freely. </p>
<p>I study the legal protection of asylum seekers, refugees, migrants and internally displaced people in Africa. I recommend that international laws and conventions be amended to explicitly include people forced by weather shocks to move across borders. They need full refugee protection. </p>
<h2>Lack of protection</h2>
<p>A variety of laws ensure refugees’ basic human rights are protected. The core of “refugee law” is constituted by the <a href="https://www.unhcr.org/about-unhcr/who-we-are/1951-refugee-convention">1951 Geneva Refugee Convention</a> – a United Nations multilateral treaty that defines who a refugee is – and its 1967 <a href="https://www.ohchr.org/en/instruments-mechanisms/instruments/protocol-relating-status-refugees">New York Protocol</a>. Refugees in Africa are also protected by the <a href="https://www.unhcr.org/media/oau-convention-governing-specific-aspects-refugee-problems-africa-adopted-assembly-heads">1969 Organisation of African Unity (OAU) Convention</a>. </p>
<p>These laws provide them with a safe haven, access to fair asylum procedures and protection from discrimination. The domestic laws of many African countries incorporate these international principles. This offers legal safeguards and support to refugees, helping them seek safety and rebuild their lives.</p>
<p>As I mention in a <a href="https://www.academia.edu/79451051/Climate_induced_displacement_in_the_Sahel_A_question_of_classification">recent study</a>, the challenge with the <a href="https://www.unhcr.org/afr/publications/legal/5ddfcdc47/handbook-procedures-criteria-determining-refugee-status-under-1951-convention.html">Refugee Convention</a> is that it rules out people who are “victims of famine or natural disaster” unless they also have a “well‑founded fear of persecution”. For instance, people fleeing Ethiopia between 1983 and 1985 due to drought would be considered refugees because they also feared persecution by the Mengistu Haile Mariam-led military dictatorship (Derg) which was <a href="https://www.hrw.org/reports/Ethiopia919.pdf">deliberately restricting food supplies</a> in parts of the country. </p>
<p>The United Nations agency mandated to aid and protect refugees, the United Nations High Commissioner for Refugee (UNHCR), follows the <a href="https://www.unhcr.org/afr/publications/legal/5ddfcdc47/handbook-procedures-criteria-determining-refugee-status-under-1951-convention.html">definition</a> provided by the Refugee Convention. As does the <a href="https://www.unhcr.org/about-unhcr/who-we-are/global-compact-refugees">Global Compact on Refugees</a>, a UN-driven blueprint for governments, international organisations and other stakeholders.</p>
<p>This means that people forcibly displaced only by environmental disasters are not entitled to refugee status, although deserving of temporary protection. </p>
<p>Within Africa, there’s a debate about whether the 1969 <a href="https://au.int/en/treaties/oau-convention-governing-specific-aspects-refugee-problems-africa">Organisation for the African Unity (OAU) Refugee Convention</a> originally included people displaced by natural disasters in its definition of “refugees”. Some practitioners believe it does, though this <a href="https://international-review.icrc.org/sites/default/files/reviews-pdf/2022-05/climate-induced-displacement-in-the-sahel-classification-918.pdf">stance</a> appears limited to human-made disasters.</p>
<p>When it comes to domestic laws, as of now, there’s no African country that recognises people fleeing natural disasters as a “refugee”. </p>
<p>There is, however, some movement. People fleeing environmental disasters are increasingly being recognised by international organisations. </p>
<p>For instance, <a href="https://www.unhcr.org/news/press-releases/unhcr-commits-climate-action-africa-protect-displaced-populations-and-foster">UNHCR</a> recognises them as a vulnerable category of persons to be protected. It has <a href="https://www.unhcr.org/news/press-releases/unhcr-commits-climate-action-africa-protect-displaced-populations-and-foster">raised awareness</a> of climate change as a driver of displacement and the need to address protection for people displaced in the context of disasters. UNHCR is also <a href="https://www.unhcr.org/sites/default/files/legacy-pdf/5975e6cf7.pdf">working on</a> addressing legal gaps related to cross-border disaster-displacement. </p>
<p>But there’s still more to be done.</p>
<h2>What needs to change</h2>
<p>People displaced by adverse weather developments should be given more than temporary protection. This will require changes to international regulations and national laws. </p>
<p>For instance, a protocol regarding climate-induced displacement should be added to the <a href="https://www.unhcr.org/media/oau-convention-governing-specific-aspects-refugee-problems-africa-adopted-assembly-heads">1969 OAU convention</a> so that displaced people who cross international borders are legally covered.</p><img src="https://counter.theconversation.com/content/212979/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cristiano d'Orsi 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>Without refugee status people aren’t able to receive valuable support, like the right to live and work in a country.Cristiano d'Orsi, Lecturer and Senior Research Fellow at the South African Research Chair in International Law (SARCIL), University of JohannesburgLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1979982023-01-31T06:13:03Z2023-01-31T06:13:03Z‘Blue marble’: how half a century of climate change has altered the face of the Earth<p>In December 1972, Nasa’s final Apollo mission <a href="https://www.nasa.gov/mission_pages/apollo/missions/apollo17.html">(Apollo 17)</a> took the iconic <a href="https://en.wikipedia.org/wiki/The_Blue_Marble">“Blue Marble”</a> photo of the whole Earth. Many, including science fiction writer <a href="https://www.nytimes.com/2008/03/19/books/19clarke.html">Arthur C. Clarke</a>, had expected that the sight of Earth from afar would instil the belief that mankind’s future lay in space. </p>
<p>Instead, it made Earth appear more unique, and has since become an icon of the global environmental movement.</p>
<p>But that portrait is now a historical artefact. Fifty years later, on December 8 2022, Nasa took a <a href="https://epic.gsfc.nasa.gov/?date=2022-12-08">new image</a> of Earth from its <a href="https://epic.gsfc.nasa.gov/">Deep Space Climate Observatory</a> approximately 1.5 million kilometres away. The photo reveals clear changes to the face of the Earth, some of which are indicative of 50 years of climate change. </p>
<h2>Sparked environmentalism</h2>
<p>The first photos taken of Earth from space were momentous historical events. In 1966, the robotic <a href="https://nssdc.gsfc.nasa.gov/imgcat/html/object_page/lo1_h102_123.html">Lunar Orbiter 1</a> (the US’s first spacecraft to orbit the Moon) sent back some early pictures including a black-and-white image of a partly shadowed Earth. The following year, a satellite called <a href="https://www.planetary.org/space-images/earth-from-ats-3">ATS-3</a> took the first colour image of Earth.</p>
<p>Then in 1968, the crew of <a href="https://www.nasa.gov/mission_pages/apollo/missions/apollo8.html">Apollo 8</a> became the first humans to see and photograph Earth from space. They took various photos through the capsule’s windows, including the famous photo known as <a href="https://en.wikipedia.org/wiki/Earthrise">“Earthrise”</a>. </p>
<p>This photo energised the environmental movement and helped to launch the <a href="https://www.earthday.org/history/">first Earth Day</a> in 1970. Held on April 22 each year, Earth Day now involves over a billion people worldwide in activities that support environmental protection. </p>
<p>In 1972, Nasa – aware of the public value of Earth images – resolved to capture an image of the whole Earth as Apollo 17 moved away from Earth orbit. Lit by the Sun and taken at a distance of 33,000 km, the photo included the first view of Antarctica from space. The image centred on Africa rather than Europe or America, and became a photographic manifesto for global justice. </p>
<p>The Earth also provided the only visible colour in space. Dominated by blue light, water and clouds, it appeared a unique environment that displayed no signs of human activity. “We live inside a blue chamber, a bubble of air blown by ourselves,” wrote cell biologist <a href="https://archive.org/details/TheLivesOfACell/mode/2up">Lewis Thomas</a> in 1973.</p>
<p>This was also the decade in which climate scientist James Lovelock put forward the <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/gaia-hypothesis">Gaia theory</a> of the Earth as a self-regulating set of combined living and non-living systems. “Earth systems science”, as it is now known, unites scientific understanding of the planet, its biosphere and its changing climate. </p>
<h2>The impact of climate change</h2>
<p>In December 2022, Nasa’s new Blue Marble photograph was compared with the original image at the University of Portsmouth’s <a href="https://www.the-whole-earth.com/">“The whole Earth: Blue Marble at 50” conference</a>. Since 1972, the planet has visibly changed.</p>
<p>The Antarctic ice sheet has visibly reduced in size, even though the main losses to the <a href="https://en.wikipedia.org/wiki/Larsen_Ice_Shelf">Larsen ice shelves</a> on the Antarctic Peninsula are not visible in this particular image. Differentiating between the permanent ice sheet and seasonal sea ice is also difficult. When the new photo was taken, sea ice was still <a href="https://climate.copernicus.eu/sea-ice">in retreat</a> from the previous winter.</p>
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<a href="https://images.theconversation.com/files/506569/original/file-20230126-22972-3mg4s2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Antarctic glacier remains of the melting Larsen A ice shelf in front of mountains." src="https://images.theconversation.com/files/506569/original/file-20230126-22972-3mg4s2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/506569/original/file-20230126-22972-3mg4s2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506569/original/file-20230126-22972-3mg4s2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506569/original/file-20230126-22972-3mg4s2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506569/original/file-20230126-22972-3mg4s2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506569/original/file-20230126-22972-3mg4s2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506569/original/file-20230126-22972-3mg4s2.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"></a>
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<span class="caption">The Larsen A ice shelf, the losses to which are not visible in the new image.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/antarctic-glacier-remains-melting-larsen-iceshelf-3274671">Armin Rose/Shutterstock</a></span>
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<p>While it can be hard to differentiate between snow and cloud in satellite images, in the original photo, some snow appears to be visible on the <a href="https://www.britannica.com/place/Zagros-Mountains">Zagros</a> and <a href="https://en.wikipedia.org/wiki/Geography_of_Iran#/media/File:Iran-geographic_map.svg">Central mountain ranges</a> in Iran (north of the Arabian Gulf). This snow has vanished entirely in the new image. However, this is again within the range of <a href="https://pubs.usgs.gov/pp/p1386g/iran.pdf">seasonal variation</a>, and <a href="https://link.springer.com/article/10.1007/s00704-014-1287-8">research</a> has failed to identify any significant long-term trend in seasonal snow cover in Iran between 1987 and 2007. </p>
<p>Most striking is the reduction in dark green vegetation in the African tropics, particularly at their northern extent. The dark shadow of <a href="https://en.wikipedia.org/wiki/Lake_Chad">Lake Chad</a> in the northern Sahara has shrunk, and forest vegetation now begins hundreds of miles further south. </p>
<p>This is consistent with evidence of desertification in north Africa’s <a href="https://theconversation.com/sahel-region-africa-72569">Sahel region</a>. <a href="https://www.sciencedirect.com/science/article/abs/pii/S0140196311003351">Research</a> found that tree density in the western Sahel declined by 18% between 1954 and 2002. And the UN Food and Agriculture Organization <a href="https://www.fao.org/3/i1757e/i1757e.pdf">estimates</a> that between 1990 and 2010, Africa lost 3–4 million hectares of forest per year, a large proportion in the Sahel. </p>
<p>Madagascar’s once-green landscape is now mainly brown. Long renowned for its ecological richness, the country is now classified a <a href="https://www.cambridge.org/core/journals/oryx/article/biodiversity-of-madagascar-one-of-the-worlds-hottest-hotspots-on-its-way-out/FDDA3F40E329166E689020CD35B42CEC">“biodiversity hotspot”</a>, a term given to a region with significant levels of biodiversity that is threatened by rapid habitat loss. </p>
<p>Many species that are found exclusively in Madagascar, including the <a href="https://small-mammals.org/2022/07/21/jumping-rat-critically-endangered/">Malagasy giant jumping rat</a>, are now at risk of extinction. The population declined by 88% between 2007 and 2019.</p>
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Read more:
<a href="https://theconversation.com/david-bowie-and-the-birth-of-environmentalism-50-years-on-how-ziggy-stardust-and-the-first-un-climate-summit-changed-our-vision-of-the-future-181033">David Bowie and the birth of environmentalism: 50 years on, how Ziggy Stardust and the first UN climate summit changed our vision of the future</a>
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<p>The original Blue Marble photo symbolised a historical turning point, from faith in unlimited progress to understanding the limitations of the planetary environment. Most satellite technology is now focused on servicing and understanding the Earth, and space exploration has confirmed just what a unique planet we inhabit.</p>
<p>The former Star Trek actor <a href="https://medium.com/starts-with-a-bang/william-shatner-cried-upon-returning-from-space-the-overview-effect-explains-why-1f3415a51815">William Shatner</a> felt this powerfully on his brief ride into space in 2021. On his return, he remarked: “I discovered that the beauty isn’t out there, it’s down here with all of us.”</p>
<p>The evidence of 50 years of environmental degradation is before our eyes. The space mission that really matters now is the mission to save Earth.</p>
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<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.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 class="fine-print"><em><span>I am author of 'Earthrise: a Short History of the Whole Earth'. It will be out February 2023.</span></em></p><p class="fine-print"><em><span>Nick Pepin has received funding from RGS, Royal Society, NERC and other organisations for research into climate change. </span></em></p><p class="fine-print"><em><span>Oliver Gruner 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>A new image has been taken of the whole Earth 50 years after the first - revealing noticeable changes to its surface.Robert Poole, Professor of History, University of Central LancashireNick Pepin, Reader in Climate Science, University of PortsmouthOliver Gruner, Senior Lecturer in Visual Culture, University of PortsmouthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1767312022-05-08T12:22:53Z2022-05-08T12:22:53ZThe window of opportunity to address increasing drought and expanding drylands is vanishing<figure><img src="https://images.theconversation.com/files/458719/original/file-20220419-20-s904jc.jpg?ixlib=rb-1.1.0&rect=17%2C98%2C5973%2C3898&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Portugal has seen little rain since October 2021. By the end of January, 45 per cent of the country was enduring 'severe' or 'extreme' drought conditions.</span> <span class="attribution"><span class="source">(AP Photo/Sergio Azenha)</span></span></figcaption></figure><p><a href="https://doi.org/10.1073/pnas.2002411117">Chile, Argentina</a> and the <a href="https://doi.org/10.1038/s41558-022-01290-z">American West</a> are in the midst of a decade-long, megadrought — the driest conditions those regions have seen in a century. And many areas in <a href="https://www.agr.gc.ca/atlas/maps_cartes/canadianDroughtMonitor/monthlyAssessments/en/2022/cdm_2201_mn_en.pdf">Western Canada</a> and the <a href="https://droughtmonitor.unl.edu/">United States</a> are experiencing extreme drought — a once in 20-year event. </p>
<p>Drought makes agriculture less productive, reduces crop yields and increases heat-related deaths. It adds to conflict and migration, as <a href="https://www.ipcc.ch/srccl/chapter/chapter-3/">marginalized people are dispossessed of their land</a>. In short, it leaves people more vulnerable. </p>
<p>Drought is part of natural climate variability, but it is also one of the many outcomes of climate change that is increasing in frequency and intensity. <a href="https://climate.nasa.gov/effects/">Droughts that used to occur in dry regions once every 10 years are now projected to occur more than four times a decade</a>, if the Earth’s average temperature warms by 4 C. </p>
<p>Unless countries dramatically reduce their emissions from burning coal, oil and natural gas, we are bound to overshoot the goal of limiting global warming to 1.5 C. Dryland areas could <a href="https://plaintextipcc.com/IPCC_AR6_WGII_Paper_3.html">expand by a quarter and encompass half of the Earth’s land area</a>, including parts of the Prairies.</p>
<p>Governments need to acknowledge that changes are already happening to dryland areas and that others can no longer be avoided, even with reduced emissions. We need to see better strategies to respond to wildfire, water scarcity and conflict, land degradation and desertification, if we are to reduce the loss of livelihoods and life from drought. </p>
<h2>Big climate changes are coming</h2>
<p><a href="https://www.usgs.gov/special-topics/drought/science/dryland-ecosystems">Drylands</a> are <a href="https://www.ipcc.ch/srccl/chapter/chapter-2/">warming twice as fast as humid areas</a>. Scientists predict that in the next 50 years, between <a href="https://doi.org/10.1073/pnas.1910114117">one billion and three billion people will be living in temperatures exceeding the climate range that has served humanity for more than 6,000 years</a>, or migrating elsewhere.</p>
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Read more:
<a href="https://theconversation.com/too-many-people-not-enough-food-isnt-the-cause-of-hunger-and-food-insecurity-179168">'Too many people, not enough food' isn't the cause of hunger and food insecurity</a>
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<p>Livelihoods and life will change fundamentally in these areas. Animal husbandry — such as livestock production — <a href="https://www.theguardian.com/global-development/2022/feb/18/somalia-crowded-camps-drought-worsens">will no longer be possible as increasing temperatures lead to the widespread death of animals</a>. And city infrastructure wasn’t built to handle intense flood events, which are <a href="https://doi.org/10.1038/s41598-019-38537-3">causing damage</a> and <a href="http://www.doi.org/10.4236/wjet.2017.53B013">increasing in many dryland areas</a>.</p>
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<img alt="A dead tree stump in front of a sandy landscape and a shallow pool of water in the background." src="https://images.theconversation.com/files/461616/original/file-20220505-17-h29ycc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/461616/original/file-20220505-17-h29ycc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/461616/original/file-20220505-17-h29ycc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/461616/original/file-20220505-17-h29ycc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/461616/original/file-20220505-17-h29ycc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/461616/original/file-20220505-17-h29ycc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/461616/original/file-20220505-17-h29ycc.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">The dry lake bed of the Wickiup Reservoir in Oregon, in September 2021.</span>
<span class="attribution"><span class="source">(AP Photo/Nathan Howard)</span></span>
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<h2>Big human changes are also coming</h2>
<p>Current climate adaptation efforts to near-term drought and flood events tend to be reactive, incremental and small. For example, Yorkton, Sask., responded to three consecutive flood events with some infrastructure change, but <a href="https://doi.org/10.3390/w14081186">enduring social learning has been lost as time passes</a>.</p>
<p>These short-sighted interventions mean vulnerable and marginalized people suffer most. Recurring drought reduces the availability of drought-risk reduction supports such as crop insurance by making insurance premiums more expensive, <a href="https://www.ewg.org/research/crop-losses-climate-crisis-cost-billions-dollars-insurance-payouts">possibly unattainable to many farmers</a>. </p>
<p>Governments must start implementing policies that aim to reduce the future impacts of drought and build farmer resilience. They might offer solutions to wind erosion and dust management or launch campaigns to reduce water consumption and promote the restoration or reclamation of landscapes. They could <a href="https://doi.org/10.3390/su132212463">embrace landscape heterogeneity strategies</a> — varieties of crops and patches of non-cultivated land — that allow bees and pollinators to thrive. After wildfires, policies and funding could <a href="https://www.ipcc.ch/srccl/chapter/chapter-3/">accelerate restoration by planting trees and vegetation</a> for wind breaks, as well as encourage farmers to plant drought-tolerant food crops.</p>
<p>Assessing the risk of climate events such as drought, flood or fire and their impacts before they occur allows for the assessment of the appropriate division of public and private responsibilities in preventing, planning for, responding to these events when they do occur.</p>
<h2>Groundwater tipping point</h2>
<p>While increasing incremental adaptation is important, large systemic change or transformational adaptation may be necessary to address worsening climate risks. These adaptations might include developing and implementing water storage technologies, changes to grazing and farming practices to preserve soil and behavioural changes to reduce water usage. </p>
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Read more:
<a href="https://theconversation.com/how-ancient-water-management-techniques-may-help-prairie-farmers-experiencing-drought-168920">How ancient water management techniques may help Prairie farmers experiencing drought</a>
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<p>There may also be residual risks that adaptation can’t address, as well as maladaptation — actions that unintentionally increase the risk of adverse outcomes due to climate change. For instance, <a href="https://doi.org/10.1038/s41598-019-40155-y">groundwater is a source of irrigation in many parts of the world and its depletion may have passed a tipping point where it cannot be recharged by precipitation</a>. </p>
<p>In water-scarce regions, <a href="https://www.fao.org/3/i7754e/i7754e.pdf">farmers may use low-quality water resources (called marginal quality waters)</a>, such as wastewater or drainage water, that may be high in salts, pathogens and heavy metals, to irrigate their crops. This can lead to salt accumulating in the soil and <a href="https://doi.org/10.1038/s41558-018-0313-8">can make the land unusable for agriculture</a>, which can then have <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/salinization">consequences for food security</a>. </p>
<p>In India, for example, hectares of land are projected to become unusable by 2050, at a cost of US$3 billion. The global economic losses of salt-induced land degradation are estimated at <a href="https://doi.org/10.3389/fsufs.2020.533781">US$27.3 billion per year</a>. In California, lack of irrigation water could cause <a href="https://www.businessinsider.com/california-water-shortage-drought-could-cause-farm-food-prices-rise-2021-6">food prices to rise globally</a>.</p>
<p>While the world’s governments consider ways to reduce emissions to limit global warming, adaptation and resilience must remain high on their list of priorities. The world is on course to overshoot its climate targets and, as the window of opportunity closes, these polices have become increasingly necessary.</p><img src="https://counter.theconversation.com/content/176731/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Margot Hurlbert receives funding from the Social Sciences and Humanities Research Council Canada.</span></em></p>If the world overshoots its climate targets, drought could cause dryland areas to expand by a quarter and encompass half the Earth’s land area, threatening lives and livelihoods.Margot Hurlbert, Canada Research Chair, Climate Change, Energy and Sustainability, University of ReginaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1665952021-09-13T14:47:44Z2021-09-13T14:47:44ZHow countries alongside the Sahara can restore productive land faster<figure><img src="https://images.theconversation.com/files/419088/original/file-20210902-19-15wl5x9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/desertscape-niger-sahelian-landscape-semi-aride-land-prone-news-photo/129374203?adppopup=true">Universal Images Group via Getty Images</a></span></figcaption></figure><p>Nigeria’s President Muhammadu Buhari is about to take over the <a href="https://www.thecable.ng/minister-buhari-to-preside-over-african-led-initiative-to-tackle-desertification">presidency</a> of the Pan-African Agency of the Great Green Wall – the continent’s effort to restore degraded cropland, grazing areas and woodlands bordering the Sahara Desert. He takes over from Mohamed Ould Ghazouani, president of Mauritania. </p>
<p>Buhari has the support of the United Nations Convention to Combat Desertification and an international accelerator platform with new funding. But based on the slow rate of progress to date and the lingering confusion about the initiative’s vision, much work remains ahead to achieve farmer prosperity. </p>
<p><a href="https://www.greatgreenwall.org/about-great-green-wall">Africa’s Great Green Wall</a> is an ambitious initiative started in 2007 by the African Union. It is now running far behind schedule. It needs to <a href="https://www.unccd.int/publications/great-green-wall-implementation-status-and-way-ahead-2030">immediately speed up</a> to reach <a href="https://www.greatgreenwall.org/2030ambition">its goals by 2030</a>, as called for by the new infusion of money and as needed by the people along the edges of the desert.</p>
<p>The original aim was to plant an 8,000km long, 15km wide tree barrier linking Dakar to Djibouti. This was to stop “desert encroachment” and protect ecosystems and human communities in the south and north of the Sahara from the harmful effects of desertification and drought. </p>
<p>The African Union and the Pan-African Agency of the Great Green Wall discarded this idea <a href="http://www.fao.org/fileadmin/templates/europeanunion/pdf/harmonized_strategy_GGWSSI-EN_.pdf">in 2012</a>, shifting the focus of efforts from trees to humans. Improving food security and livelihoods will be linked to containing desertification. </p>
<p>The new vision that emerged in 2012 is to establish a mosaic of green and productive landscapes across a broad zone surrounding the Sahara. The aim is to restore whole agroecosystems through land management practices that enhance the livelihoods of the rural people.</p>
<p>The goals set for the Green Wall by 2030 are: </p>
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<li><p>restore 100 million hectares of degraded land</p></li>
<li><p>sequester 250 million tons of carbon</p></li>
<li><p>create 10 million green jobs in rural areas.</p></li>
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Read more:
<a href="https://theconversation.com/africas-got-plans-for-a-great-green-wall-why-the-idea-needs-a-rethink-78627">Africa's got plans for a Great Green Wall: why the idea needs a rethink</a>
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<p>Reported progress has been slow and uneven, say reports commissioned by the <a href="https://www.unccd.int/publications/great-green-wall-implementation-status-and-way-ahead-2030">United Nations Convention to Combat Desertification</a> and the <a href="https://documents.worldbank.org/en/publication/documents-reports/documentdetail/343311608752196338/sustainable-land-management-in-the-sahel-lessons-from-the-sahel-and-west-africa-program-in-support-of-the-great-green-wall-sawap">World Bank</a>. Only some 18 million hectares have been restored so far, and movement in some countries is lagging. The <a href="http://www.fao.org/3/i6476e/i6476e.pdf">Food and Agriculture Organization</a> and <a href="https://www.unccd.int/publications/great-green-wall-implementation-status-and-way-ahead-2030">United Nations</a> have estimated that the pace must increase by a factor of 10 if the 2030 goals are to be reached. </p>
<p>Fortunately, help is on the way. On 11 January 2021 at the One Planet Summit in Paris, world leaders <a href="https://www.oneplanetsummit.fr/en/coalitions-82/great-green-wall-accelerator-193">announced</a> financial support of US$16 billion over five years – almost 10 times as much as international donors contributed between 2010 and 2019. A new multi-stakeholder platform will accelerate the Green Wall process through better coordination, implementation, monitoring, and tracking of impact. This <a href="https://www.unccd.int/actionsgreat-green-wall-initiative/great-green-wall-accelerator">accelerator</a> will be managed by the agency headed by Buhari. </p>
<p>The task is a challenge but far from hopeless. Successful cases of regreening do exist, as shown by the <a href="http://www.fao.org/3/i6476e/i6476e.pdf">Food and Agriculture Organization’s map of 2016</a>. The accelerator would do well to study what has worked for <a href="https://www.wri.org/research/scaling-regreening-six-steps-success">regreening</a> in various <a href="https://knowledge.unccd.int/publications/restoring-african-drylands-farmer-and-community-managed-restoration">cases</a>. </p>
<p>The following suggestions build on our experience and examination of successful cases.</p>
<h2>Build on past successes</h2>
<p>In the densely populated parts of southern Niger, farmers have <a href="http://www.etfrn.org/file.php/492/1-9-toudou.pdf">regreened</a> more than five million hectares since 1985 by adding at least 200 million trees to their farming systems. They did this not by planting trees, but by protecting and managing natural regeneration from the tree stumps already there and from the seedlings that emerge naturally from the soil. </p>
<p>On <a href="http://www.etfrn.org/file.php/488/1-5-allen.pdf">Mali’s Seno Plains</a>, around half a million hectares have been regreened by farmers since the mid-1990s. In <a href="http://www.etfrn.org/file.php/484/1-1-tappan.pdf">central Senegal</a>, hundreds of villages are now greener than 30 years ago. In <a href="http://www.etfrn.org/file.php/487/1-4-belemvire.pdf">Burkina Faso</a> and <a href="http://www.etfrn.org/file.php/485/1-2-hassane.pdf">Niger</a>, farmers have restored several hundred thousand hectares of barren degraded land to productivity by using simple water harvesting techniques.</p>
<p>These and other successful cases of restoration were driven and achieved through grassroots community mobilisation and the independent efforts of millions of farm households. They were also encouraged by some non-governmental organisations (NGOs) and development projects. They produced massive results at a very low cost. </p>
<p>Many of these efforts have not been officially reported as contributions to the Green Wall, as they happened outside the budgets and control of the national forestry departments. </p>
<p>The Pan African Agency now needs to convince governments to recognise and vigorously support investment in bottom-up, cost-effective, grassroots initiatives of this kind. This may not be the preferred choice of the government agencies through which funds are likely to pass. But many years of slow progress suggest that it is the only route to success. </p>
<h2>No need to plant</h2>
<p>The idea of the narrow green line across Africa still persists in too many minds. It is past the time to let it go. More trees are indeed needed, but planting is an <a href="http://bit.ly/38cwSQp">expensive and precarious</a> way to establish them in arid and semi-arid lands. </p>
<p>Budgets can be stretched tremendously by shifting to proven methods that achieve evergreening faster than conventional tree planting. We have <a href="https://www.wri.org/research/scaling-regreening-six-steps-success">discovered</a> that regreening is almost always led by farmers. Farmers can protect and <a href="http://www.etfrn.org/file.php/489/1-6-winterbottom.pdf">manage the natural regeneration</a> of trees and shrubs on land they manage. There are also <a href="http://www.fao.org/3/t0321e/t0321e-10.htm">proven practices</a> for rainwater harvesting and soil and water conservation. </p>
<h2>Clarify goals and track progress</h2>
<p>The shift in vision has made it more challenging to track the progress of the Green Wall. It is easier to imagine and monitor a long wall of planted trees than a comprehensive restoration initiative. New baselines must be created. All progress should be counted, not only that which comes from government spending. The Pan African Agency should insist on greater clarity and consistency in what needs to be monitored. </p>
<h2>Collaborate with the non-governmental sector</h2>
<p>The non-governmental sector must complement the efforts of government departments. The members of the <a href="https://www.evergreening.org/">Global EverGreening Alliance</a> have pledged their joint capacity to restoring hundreds of millions of hectares of degraded lands. The alliance includes nearly all of the major development and conservation NGOs around the world, and those working in the Sahel. </p>
<p>The NGO community is a tremendous resource. The Pan African Agency could greatly expand its impact by working with it. </p>
<p>Restoring the 100 million hectares of degraded lands surrounding the Sahara is possible. But the mindsets in governments and donor organisations must change. Success so far has been largely due to grassroots efforts with only modest support from external sources. Thus, the strategy going forward is clear: invest in scaling-up the proven successes, and let go of the ones that have failed.</p>
<p>While President Buhari has not indicated the direction the agency will take under his chairmanship, we hope he can follow these recommendations.</p><img src="https://counter.theconversation.com/content/166595/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lars Laestadius previously worked as a consultant to FAO on drylands monitoring. He is a Fellow with the Global EverGreening Alliance.</span></em></p><p class="fine-print"><em><span>Chris Reij and Dennis Garrity do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Africa’s Great Green Wall must immediately speed up to meet the needs of people along the edges of the Sahara Desert.Lars Laestadius, Adjunct Research Scientist, Swedish University of Agricultural SciencesChris Reij, Sustainable land management specialist, World Resources InstituteDennis Garrity, Board Chair, Global EverGreening Alliance & Distinguished Senior Fellow, World Agroforestry (ICRAF), Center for International Forestry Research – World Agroforestry (CIFOR-ICRAF)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1626652021-06-17T07:58:34Z2021-06-17T07:58:34ZAfrica’s drylands are getting more support. How to make the most of this<figure><img src="https://images.theconversation.com/files/406141/original/file-20210614-73350-gsxewg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Farmers working the land in the Western Sahara, Egypt. </span> <span class="attribution"><span class="source">DeAgostini/Getty Images</span></span></figcaption></figure><p>The United Nations (UN) recently launched the <a href="https://www.decadeonrestoration.org/">Decade on Ecosystem Restoration</a> to prevent, halt and reverse the degradation of ecosystems worldwide. It is a response to evidence that our current abuse of nature has <a href="https://www.ipcc.ch/sr15/chapter/spm/">accelerated global warming</a> and <a href="https://ipbes.net/global-assessment">degraded natural resources</a> to a degree that threatens <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(18)31788-4/fulltext">the wellbeing</a> of people. </p>
<p>The Decade will use overseas development aid to influence land use policies that align with <a href="https://www.decadeonrestoration.org/strategy">its 10 point strategy</a>. This will be channelled through instruments such as <a href="https://www.globallandscapesforum.org/publication/the-drylands-sustainable-landscapes-impact-program-local-action-for-impact-at-scale/">the Global Environment Facility’s drylands programme</a> and the <a href="https://www.unccd.int/actions/impact-investment-fund-land-degradation-neutrality">Land Degradation Neutrality Fund</a>. </p>
<p>These efforts will be particularly important to <a href="https://afr100.org/content/afr100-restoring-future-africa">Africa’s drylands</a>. Drylands are typically low rainfall areas where high temperatures and a lack of water <a href="https://www.millenniumassessment.org/documents/document.291.aspx.pdf">constrains</a> crop, animal and forest production.</p>
<p>In Africa, drylands <a href="https://www.globallandscapesforum.org/glf-news/africas-drylands-near-tipping-point-but-local-communities-could-save-it-experts-say/">cover</a> 60% of the continent. They are <a href="https://www.globallandscapesforum.org/glf-news/africas-drylands-near-tipping-point-but-local-communities-could-save-it-experts-say/">home to over</a> 525 million people who depend on rainfed agriculture and livestock husbandry. The weather conditions, combined with the effects of human activity on the land, make drylands highly vulnerable to land degradation, known as desertification. This <a href="https://www.iucn.org/resources/issues-briefs/drylands-and-land-degradation">includes</a> the loss of soil, soil fertility and vegetation.</p>
<p>Unpredictable climate and challenging socio-ecological conditions have shaped societies with astonishing and innovative coping capacities. For instance, dryland pastoralists <a href="https://www.mamopanel.org/media/uploads/files/Livestock-report-MaMo-2020-def.pdf">produce more than</a> half of Africa’s red meat and milk. </p>
<p>However, the climate crisis, with temperatures rising <a href="https://iopscience.iop.org/article/10.1088/1748-9326/aac3e5">1.5 times faster</a> then anywhere else in the world, threatens the balance communities have created in this landscape. Conflicts over resources are <a href="https://www.americanscientist.org/article/dying-for-a-drink">on the rise</a> and so is <a href="https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjqwrKlg5nxAhV8EWMBHWi3DEEQFjAAegQIAxAD&url=https%3A%2F%2Freliefweb.int%2Freport%2Fmali%2Fdesert-conditions-and-risks-mixed-migration-routes-through-west-africa&usg=AOvVaw3IHlEDe2xQM32Kg8QTULt0">migration</a>.</p>
<p>Investments in Africa’s drylands are needed to restore this balance and sustain productivity while catering to the next generation’s aspirations: providing job opportunities and turning local business into engines for development.</p>
<h2>Neglected and underfunded</h2>
<p>Drylands are an overlooked biome. This is rooted in the origins of the <a href="https://www.cbd.int/rio/">Rio conventions</a> – three conventions created with the aim to promote a sustainable planet for future generations.</p>
<p>One of these conventions, the <a href="https://www.unccd.int/">Convention to Combat Desertification</a>, was adopted in 1994 to address the concerns of African leaders about poverty, drought and food insecurity. But, unlike climate change and biodiversity, programmes under this convention – which aimed to halt soil erosion and the loss of soil fertility – <a href="https://pubs.iied.org/sites/default/files/pdfs/migrate/11017IIED.pdf">were not perceived</a> to contribute to a global public good. This left the Convention to Combat Desertification <a href="https://pubs.iied.org/sites/default/files/pdfs/migrate/11017IIED.pdf">chronically underfunded</a> and drylands remained a lower environmental priority.</p>
<p>With international environmental funds not available, the first leadership of the convention wanted to tap into development funding. They did this by painting a <a href="https://www.undp.org/content/dam/undp/library/Environment%20and%20Energy/sustainable%20land%20management/The%20Global%20Drylands%20Initiative,%202001-09%20-%20Challenge%20Paper-%20Poverty%20and%20the%20Drylands.pdf">bleak picture</a> of degraded lands, rapid population growth and inadequate livelihood options. But, for years to come, this made private investors and development financiers shy away from investing in agricultural enterprises in Africa’s drylands.</p>
<p>Now, with the launch of the Decade on Ecosystem Restoration, much more funding will be channelled into drylands through projects on the ground.</p>
<h2>Making an impact</h2>
<p>To ensure that these investments make the most impact, there are a few lessons to bear in mind. </p>
<p>We recently attended the <a href="https://events.globallandscapesforum.org/africa-2021/">Global Landscapes Forum</a>. This brought together experts, policymakers, businesses, investors and local communities. It involved 232 speakers, with 127 from Africa, and 50% of whom were women. They gave a clear message about how funds can lead to change.</p>
<p>Land degradation in drylands is a multi-faceted problem. Single sectoral approaches – like maximising crop yields or banning fires – won’t work. The solution for sustainable African drylands is to ensure there is optimal vegetation, water and soil resources under the constraints of climate change and inadequate human and financial resources. </p>
<p>All of these measures are important because restoration alone won’t work. More is needed to solve the underlying economic problems of population growth and insufficient income opportunities in the drylands. Opening up economic opportunities through land restoration will.</p>
<p>To achieve this, modern innovations and science need to work hand in hand with local practices and knowledge to produce the quality and quantity of products needed to build investment cases in restoration. One example of this is the
<a href="https://www.globallandscapesforum.org/wp-content/uploads/2021/06/GLF-Africa-2021-white-paper-Innovative-solutions-to-strengthen-resilience-in-the-drylands.pdf">Supporting Pastoralism and Agriculture in Recurrent and Protracted Crises programme</a>, which
brings together scientists and local communities across sub-Saharan Africa. It links pastoralists and their milk and meat products to investors as well as markets.</p>
<p>Funding is needed in capacity building for land-use practices and business skills. In addition there need to be investments in equipment and infrastructure as well as stronger local governance and institutions.</p>
<p>Approaches must give responsibility and rights to local communities, the owners and custodians of the land. They must be equal partners in restoration efforts. Through years of implementing landscape restoration activities, it is clear that <a href="https://www.globallandscapesforum.org/wp-content/uploads/2021/05/GLF-Africa-2021-white-paper-Roots-of-Restoration.pdf">only programmes</a> that co-design interventions with local communities – which assure equal benefits and access rights – lead to long-lasting change.</p>
<p>Women and young people, whose lives are <a href="https://www.foreststreesagroforestry.org/thinking-of-tomorrow-women-essential-to-successful-forest-and-land-restoration-in-africa/">disproportionately affected</a> by degradation, must be at the fore. </p>
<p>In Kenya, for example, these areas are predominantly inhabited by patriarchal communities. Women are responsible for nurturing the children and, without productive lands for food and firewood, their lives are very challenging. Various progressive pieces of legislation were enacted in the recent past. However women <a href="https://land.igad.int/index.php/documents-1/countries/kenya/gender-3/625-women-s-land-and-property-rights-in-kenya/file">continue to be</a> marginalised and discriminated against. </p>
<p>Women must be supported in leading inter-generational dialogues within their families and clans. The idea would be that these would foster a shift in social norms to ensure equitable access to land regardless of gender or age. </p>
<p>As for young people, the traditional way of life can no longer offer a prosperous future for them all and off farm opportunities are very limited. </p>
<p>There are encouraging stories of new generations of entrepreneurs in dryland areas that are turning community-based NGO activities into sustainable businesses. <a href="https://sahelconsult.com/alddn/">Sahel Consulting</a>, for example, links private investors to women dairy producers in Nigeria. <a href="https://events.globallandscapesforum.org/africa-2021/speaker/fatima-kaba/">Enda Energie is an initiative</a> that links women cooperatives to personal care and cosmetic markets <a href="http://www.fao.org/in-action/action-against-desertification/news-and-multimedia/detail/en/c/1177465/">where they</a> sell fruits. </p>
<p>In addition carbon credits can be a real incentive for investors in clean energy technologies, such as <a href="https://marketplace.goldstandard.org/collections/projects/products/solar-cooking-refugee-families-chad">solar cooking</a> or <a href="https://marketplace.goldstandard.org/collections/projects/products/kenya-biogas-programme">biogas</a>. Governments must recognise the potential of drylands so these initiatives can flourish. This includes ensuring people have access to markets and finance so they can sustainably scale up. </p>
<p>Finally, external funding programmes must support the de-risking of pastoralism and enhanced resilience to shocks. This can be done through, <a href="https://www.globallandscapesforum.org/wp-content/uploads/2021/06/GLF-Africa-2021-white-paper-Innovative-solutions-to-strengthen-resilience-in-the-drylands.pdf">for instance</a>, index based financing and insurance.</p>
<p><em>Kimberly Merten, Cora van Osten, Adinda Hassan and Sophie Callahan from the Global Landscape Forum contributed to this article.</em></p><img src="https://counter.theconversation.com/content/162665/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Anja Gassner receives funding from the International Climate Initiative (IKI) of the German Federal Ministry for the Environment, Nature Conservation, and Nuclear Safety (BMU); German Federal Ministry for Economic Cooperation and Development and Robert Bosch Stiftung</span></em></p><p class="fine-print"><em><span>Philip Dobie receives funding from the German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety.</span></em></p><p class="fine-print"><em><span>Robert Nasi receives funding from the International Climate Initiative (IKI) of the German Federal Ministry for the Environment, Nature Conservation, and Nuclear Safety (BMU); German Federal Ministry for Economic Cooperation and Development and Robert Bosch Stiftung</span></em></p>A changing climate threatens the balance that communities in drylands have created.Anja Gassner, Global Landscapes Forum science advisor and Senior Scientist, Center for International Forestry Research – World Agroforestry (CIFOR-ICRAF)Philip Dobie, Senior Fellow, Center for International Forestry Research – World Agroforestry (CIFOR-ICRAF)Robert Nasi, Director General , Centre for International Forestry ResearchLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1595962021-06-14T15:49:49Z2021-06-14T15:49:49ZSudan’s ‘forgotten’ pyramids risk being buried by shifting sand dunes<figure><img src="https://images.theconversation.com/files/406165/original/file-20210614-47555-wwdvzo.jpg?ixlib=rb-1.1.0&rect=6%2C0%2C4354%2C2197&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Martchan / shutterstock</span></span></figcaption></figure><p>The word “pyramid” is synonymous with Egypt, but it is actually neighbouring Sudan that is home to the world’s largest collection of these spectacular ancient structures.</p>
<hr>
<iframe id="noa-web-audio-player" style="border: none" src="https://embed-player.newsoveraudio.com/v4?key=x84olp&id=https://theconversation.com/sudans-forgotten-pyramids-risk-being-buried-by-shifting-sand-dunes-159596&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>
<hr>
<p>Beginning around 2500BC, Sudan’s ancient Nubian civilisation left behind more than 200 pyramids that rise out of the desert across three <a href="http://www.sudarchrs.org.uk">archaeological</a> sites: El Kurru, Jebel Barkal and Meroe, in addition to temples, tombs and royal burial chambers.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/406147/original/file-20210614-65156-43ifun.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map of Sudan with dots" src="https://images.theconversation.com/files/406147/original/file-20210614-65156-43ifun.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/406147/original/file-20210614-65156-43ifun.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=710&fit=crop&dpr=1 600w, https://images.theconversation.com/files/406147/original/file-20210614-65156-43ifun.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=710&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/406147/original/file-20210614-65156-43ifun.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=710&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/406147/original/file-20210614-65156-43ifun.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=892&fit=crop&dpr=1 754w, https://images.theconversation.com/files/406147/original/file-20210614-65156-43ifun.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=892&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/406147/original/file-20210614-65156-43ifun.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=892&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Nubian archaeological sites in modern-day Sudan and Egypt.</span>
<span class="attribution"><a class="source" href="https://www.google.com/maps/d/u/0/viewer?ie=UTF8&hl=en&msa=0&t=h&ll=21.58867450404889%2C35.418475937499984&spn=8.386687%2C5.141599&source=embed&mid=1tzaCtXWcus01krv982rpD6CcMyA&z=5">Google Maps</a></span>
</figcaption>
</figure>
<p>Despite being smaller than the famous Egyptian pyramids of Giza, <a href="http://www.sudarchrs.org.uk/wp-content/uploads/2019/03/SARS_SN04_Hinkel_opt.pdf">Nubian pyramids</a> are just as magnificent and culturally valuable. They even offer a crowd-free experience for intrepid tourists.</p>
<p>Built of sandstone and granite, the steeply-sloping pyramids contain chapels and burial chambers decorated with illustrations and inscriptions carved in hieroglyphs and Meroitic script celebrating the rulers’ lives in Meroe – a wealthy Nile city and the seat of power of Kush, an ancient kingdom and rival to Egypt.</p>
<p>Located about 220km north of the capital Khartoum, the cultural gem of Meroe is now one of Sudan’s most significant <a href="https://whc.unesco.org/en/list/1336/">Unesco world heritage sites</a>. However a lack of preservation, severe weather conditions and negligent visitors have all taken their toll on its monuments. Back in the 1880s, for instance, the Italian explorer Giuseppe Ferlini <a href="https://www.nytimes.com/2010/05/22/arts/22iht-melik22.html">blew up several pyramids</a> in his search for Kushite treasure, leaving many of the tombs missing their pointy tops. Many more of Sudan’s other pyramids were subsequently plundered and destroyed by looters.</p>
<h2>Shifting sands</h2>
<p>These days sandstorms and shifting sand dunes pose the biggest threat to Sudan’s ancient heritage sites. This phenomenon is nothing new, and was even chronicled thousands of years ago. An inscription found in a temple from the 5th century BC describes a Kushite king giving an order to <a href="http://www.sudarchrs.org.uk/wp-content/uploads/2019/03/SARS_SN16_Munro_opt.pdf">clear out sand from the pathway</a>: </p>
<blockquote>
<p>His Majesty brought a multitude of hands, to wit, men and women as well as royal children and chiefs to carry away the sand; and his Majesty was carrying away sand with his hand(s) himself, at the forefront of the multitude for many days.</p>
</blockquote>
<p>But today the threat has been exacerbated by climate change, which has made the land more arid and sandstorms more frequent. Moving sands can engulf entire houses in rural Sudan, and cover <a href="https://www.tandfonline.com/doi/abs/10.1080/13504509409469874">fields, irrigation canals and riverbanks</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/406171/original/file-20210614-102836-1vnwmgk.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Pyramids covered by sand" src="https://images.theconversation.com/files/406171/original/file-20210614-102836-1vnwmgk.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/406171/original/file-20210614-102836-1vnwmgk.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/406171/original/file-20210614-102836-1vnwmgk.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/406171/original/file-20210614-102836-1vnwmgk.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/406171/original/file-20210614-102836-1vnwmgk.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/406171/original/file-20210614-102836-1vnwmgk.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/406171/original/file-20210614-102836-1vnwmgk.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sand creeps over a pyramid at the northern royal cemetery of Meroe.</span>
<span class="attribution"><span class="source">Ahmed Mahmoud</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>While some archaeologists believe sand movement helps to <a href="https://thearabweekly.com/egyptologists-uncover-lost-golden-city-buried-under-sand">preserve ancient artefacts from thieves</a>, it is known to be detrimental to excavated sites, reburying them beneath the desert. Sand blown by the wind also <a href="https://research-repository.st-andrews.ac.uk/handle/10023/17889">erodes delicate stonework and sculptures</a>.</p>
<h2>Fighting back against desertification</h2>
<p>The best way to combat sand movement and desertification is to increase the vegetation cover, and one ambitious African-led reforestation project is leading the way.</p>
<p>Bringing together more than 20 nations, the <a href="https://www.greatgreenwall.org/about-great-green-wall">Great Green Wall</a> is a multi-billion dollar movement to stop the spread of the Sahara Desert by restoring 100 million hectares of land across the continent from Senegal in west Africa to Djibouti in the east. The intention is to cultivate the largest living barrier of trees and plants on the planet, with Sudan having the longest stretch of the “wall”.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/398749/original/file-20210504-13-1g7ruou.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map of Africa with green line and shaded orange bit." src="https://images.theconversation.com/files/398749/original/file-20210504-13-1g7ruou.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/398749/original/file-20210504-13-1g7ruou.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=366&fit=crop&dpr=1 600w, https://images.theconversation.com/files/398749/original/file-20210504-13-1g7ruou.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=366&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/398749/original/file-20210504-13-1g7ruou.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=366&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/398749/original/file-20210504-13-1g7ruou.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=460&fit=crop&dpr=1 754w, https://images.theconversation.com/files/398749/original/file-20210504-13-1g7ruou.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=460&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/398749/original/file-20210504-13-1g7ruou.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=460&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 great green wall will run through the Sahel region to the south of the Sahara.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:Great_green_wall_map.svg">sevgart / wiki</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Only <a href="https://www.theguardian.com/environment/2020/sep/07/africa-great-green-wall-just-4-complete-over-halfway-through-schedule">4% of the target area</a> has been covered so far, with big variations from country to country. When it is more complete, this experimental project will hopefully limit the frequency of dust storms and slow the movement of sand onto fertile lands and Unesco sites in northern Sudan. It will also contribute to tackling the extreme heatwaves in semi-arid areas such as the capital Khartoum, where the temperature goes well above 40°C during summer. </p>
<p>However, monitoring the impact of the project, which spans 5,000 miles across Africa, requires “big picture” data. This comes from the latest satellites and remote sensing technologies.</p>
<h2>Sand-tracking satellites</h2>
<p>Satellite imagery can provide valuable information about sand movement. For instance satellites are used to monitor the dust storms that transport sand from the Sahara across the Atlantic Ocean to supply the <a href="https://iopscience.iop.org/article/10.1088/1748-9326/1/1/014005#:%7E:text=Here%2520we%2520show%2520that%2520about,or%25200.2%2525%2520of%2520the%2520Sahara.">Amazon rainforest</a> with essential <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015GL063040">fertilising nutrients</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/406158/original/file-20210614-73475-1xk1j1f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Satellite image of Sudan with large dust clouds" src="https://images.theconversation.com/files/406158/original/file-20210614-73475-1xk1j1f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/406158/original/file-20210614-73475-1xk1j1f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=474&fit=crop&dpr=1 600w, https://images.theconversation.com/files/406158/original/file-20210614-73475-1xk1j1f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=474&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/406158/original/file-20210614-73475-1xk1j1f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=474&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/406158/original/file-20210614-73475-1xk1j1f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=596&fit=crop&dpr=1 754w, https://images.theconversation.com/files/406158/original/file-20210614-73475-1xk1j1f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=596&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/406158/original/file-20210614-73475-1xk1j1f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=596&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Dust storm over Sudan, August 2017.</span>
<span class="attribution"><span class="source">NASA MODIS</span></span>
</figcaption>
</figure>
<p>But what about on a smaller scale? How do you predict if and when sand will submerge a field, a watering hole – or a pyramid?</p>
<p>In my own research I have previously used multiple overlapping images taken from aeroplanes to generate digital elevation models for sand dunes in northern Sudan. That led to my current PhD research which focuses on monitoring the movement of sand dunes using satellite optical and radar <a href="https://www.mdpi.com/2072-4292/12/20/3410">images</a>, airborne laser imagery and other techniques. My research also investigates the influence of factors such as wind speed and direction, presence of vegetation and topography.</p>
<p>Colleagues and I ultimately want to develop our understanding of how sand dunes grow in size and how they migrate across the desert. This will enable us to monitor the effectiveness of interventions such as vegetation barriers, helping to combat desertification and climate change and to ensure people in Sudan are able to grow enough food. And we may even be able to predict when and where those pyramids will be buried – and what we can do to prevent it.</p><img src="https://counter.theconversation.com/content/159596/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ahmed Mahmoud receives funding from the Ministry of Higher Education and Scientific Research-Sudan/ University of Nottingham and the British Geological Survey University Funding Initiative (BUFI). He is affiliated with the University of Nottingham and the British Geological Survey. </span></em></p>Desertification and climate change are threatening ancient sites in the Sahara.Ahmed Mutasim Abdalla Mahmoud, PhD Researcher, Sand Movement in Sudan, University of NottinghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1487032020-10-29T14:55:49Z2020-10-29T14:55:49ZCentral Asia risks becoming a hyperarid desert in the near future<figure><img src="https://images.theconversation.com/files/366451/original/file-20201029-15-fi2ie7.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">Jakub Czajkowski / shutterstock</span></span></figcaption></figure><p>Around 34 million years ago, sudden climate change caused ecological breakdown in Central Asia. This ancient event, triggered by rapid drops in temperature and atmospheric carbon dioxide, permanently affected biological diversity in the region. Large areas of Mongolia, (geographic) Tibet and north-western China suddenly became hyperarid deserts with little vegetation cover – and stayed that way for almost 20 million years.</p>
<p>This was a surprising finding of <a href="https://advances.sciencemag.org/content/6/41/eabb8227">new research</a> I carried out with colleagues from across Europe and China, in which we reconstructed the past 43 million years of evolutionary history for the steppe, semi-desert and desert ecosystems of Central Asia (the biogeographical and political conceptions of “Central Asia” differ and we use the former: our research area is shown below). </p>
<p>Many scientists had <a href="https://cp.copernicus.org/articles/4/153/2008/">previously thought</a> that this region was forested for much of that time and only grew drier later on, culminating today in massive, exceptionally arid Asian deserts such as the Gobi and Taklimakan.</p>
<figure class="align-center ">
<img alt="image showing a map, some plants and a cross section of some mountains and a desert" src="https://images.theconversation.com/files/366386/original/file-20201029-15-1gs6mtx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/366386/original/file-20201029-15-1gs6mtx.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/366386/original/file-20201029-15-1gs6mtx.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/366386/original/file-20201029-15-1gs6mtx.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/366386/original/file-20201029-15-1gs6mtx.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/366386/original/file-20201029-15-1gs6mtx.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/366386/original/file-20201029-15-1gs6mtx.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=533&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The modern Central Asian steppe-desert (A), characteristic plant families (B), and an altitudinal profile illustrating vegetation belts of the steppe subtypes (C).</span>
<span class="attribution"><span class="source">Science Advances 2020; 6: eabb8227</span></span>
</figcaption>
</figure>
<p>We found that fossil pollen combined with mammal fossils, geological and climatic evidence – all preserved inside ancient rocks – told a different tale. Ancient “wet” steppe-deserts that received enough precipitation to maintain high biodiversity already existed during the late Eocene (40 to 34 million years ago), but suddenly became much colder and drier over an event called the Eocene‒Oligocene Transition (EOT). </p>
<p>Scientists already knew that global climate cooling in this period caused the formation of a <a href="https://www.nature.com/articles/nature08447?platform=hootsuite">permanent Antarctic ice-sheet</a>, but what happened on different continents is less clear. Our new study found that the lowlands of Central Asia became hyperarid deserts with little vegetation cover. The lack of food resources meant that larger animals were mainly replaced by small mammals like rodents, rabbits and hares. </p>
<figure class="align-center ">
<img alt="Three bits of fossilised pollen viewed under a microscope" src="https://images.theconversation.com/files/366235/original/file-20201028-15-1q38yll.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/366235/original/file-20201028-15-1q38yll.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=292&fit=crop&dpr=1 600w, https://images.theconversation.com/files/366235/original/file-20201028-15-1q38yll.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=292&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/366235/original/file-20201028-15-1q38yll.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=292&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/366235/original/file-20201028-15-1q38yll.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=367&fit=crop&dpr=1 754w, https://images.theconversation.com/files/366235/original/file-20201028-15-1q38yll.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=367&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/366235/original/file-20201028-15-1q38yll.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=367&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Scanning electron microscope (SEM) images of fossil pollen used to reconstruct the ancient ecosystems of Central Asia. Scale bars represent 5 micrometres (0.005 mm).</span>
<span class="attribution"><span class="source">Carina Hoorn and Fang Han</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>This hyperaridity lasted for millions of years afterwards, and plants only recovered when the climate became temporarily wetter around 15 million years ago. But now, the major species were small, non-woody herbs, not the salt and drought- tolerant shrubs that had dominated before the ecological collapse. Despite large parts of Central Asia being very dry today, these shrubs (<em>Nitraria</em> and <em>Ephedra</em>) never again recovered their position of ecological prominence. We still don’t fully understand why, but it shows that populations can be permanently altered by sudden environmental changes even if widespread extinctions don’t occur. </p>
<p>This finding is particularly relevant today, because atmospheric carbon dioxide levels and climate are again changing rapidly. Given what we now know about the Asian steppe-desert’s climatic and ecological history, it is unlikely that these ecosystems will ever recover their present biological diversity if forced into a new state.</p>
<h2>History repeats itself</h2>
<p>The modern steppe-desert is the largest ecoregion of its kind in the world, hosting a lot more biodiversity than you might expect. Dry-adapted grasses and herbs support an array of wildlife, many of which are endemics (native to, and living only in, that region). These unique flora and fauna have evolved partly as a result of immense geological and climatic diversity: today Central Asia is home to some of the oldest deserts known, as well as the highest mountains outside of the Himalayas.</p>
<figure class="align-center ">
<img alt="Flat grassy land with snowy mountains in the background" src="https://images.theconversation.com/files/366212/original/file-20201028-17-1hw5ipq.jpg?ixlib=rb-1.1.0&rect=0%2C9%2C6252%2C3809&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/366212/original/file-20201028-17-1hw5ipq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=367&fit=crop&dpr=1 600w, https://images.theconversation.com/files/366212/original/file-20201028-17-1hw5ipq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=367&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/366212/original/file-20201028-17-1hw5ipq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=367&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/366212/original/file-20201028-17-1hw5ipq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=461&fit=crop&dpr=1 754w, https://images.theconversation.com/files/366212/original/file-20201028-17-1hw5ipq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=461&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/366212/original/file-20201028-17-1hw5ipq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=461&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Meadow steppes in the Qilian Mountains of northern China, surrounded by alpine steppe and tundra. Topographic growth in the Tibetan region over many millions of years has created new high-elevation ecosystems for cold-tolerant biota to thrive.</span>
<span class="attribution"><span class="source">Xiaoming Wang / imaggeo.egu.eu</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Ancient climate change and geological forces have shaped the steppe-desert through time. The collision of India with Asia, formation of the Tibetan Plateau and uplift of the Himalaya, Altai and Hangay mountain ranges created extreme altitudinal variation, as well as distinct <a href="https://www.nationalgeographic.org/encyclopedia/rain-shadow/">rain shadows</a> of dry land on the downwind side. This generated a mosaic of habitats, and in turn, an astonishing number of species who call the region home.</p>
<p>But now the steppe-desert’s biodiversity is under severe threat from human-induced climate change and land degradation. Growing seas of sand are claiming native steppes, <a href="https://www.nytimes.com/interactive/2016/10/24/world/asia/living-in-chinas-expanding-deserts.html">imposing desertification</a> at unprecedented rates. Evidence from the past shows us that this is a sign of impending ecosystem breakdown – and it will cause irreversible changes and loss of biodiversity if allowed to continue.</p>
<h2>Claimed by the desert</h2>
<p>Desertification in Asia has major implications for humans too. It now threatens almost half a billion people, many of whom are finding it increasingly difficult to make a living in communities dominated by agriculture. Crops are ravaged by drought, livestock are losing grazing pastures, and deserts are growing towards the cities. </p>
<figure class="align-left ">
<img alt="Large sand dunes" src="https://images.theconversation.com/files/366251/original/file-20201028-23-aiirbj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/366251/original/file-20201028-23-aiirbj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/366251/original/file-20201028-23-aiirbj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/366251/original/file-20201028-23-aiirbj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/366251/original/file-20201028-23-aiirbj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/366251/original/file-20201028-23-aiirbj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/366251/original/file-20201028-23-aiirbj.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">Sand sea of the Taklimakan Desert. Similarly hyperarid deserts may have spread across Central Asia in the past as a result of rapid climate change.</span>
<span class="attribution"><span class="source">Matthias Alberti / imaggeo.egu.eu</span></span>
</figcaption>
</figure>
<p>Model predictions from the <a href="https://www.ipcc.ch/site/assets/uploads/2018/02/WGIIAR5-Chap24_FINAL.pdf">Intergovernmental Panel on Climate Change (IPCC)</a> and recent climate records show that interior Asia is fast becoming one of the hottest and driest places on the planet. Major predicted changes include highly reduced vegetation cover and rapid, severe species losses, along with more unreliable rainfall and high dust emissions generated by widespread desertification and erosion. </p>
<p>This new hyperarid desert ecosystem phase would resemble the inhospitable, barren landscapes that spread 34 million years ago. Lessons from the past make it clear that current human-induced global changes must be urgently halted in order to preserve the Asian steppe, which has now become one of the world’s most endangered habitats.</p><img src="https://counter.theconversation.com/content/148703/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Natasha Barbolini receives funding from the European Research Council (grant MAGIC 649081), the Swedish Research Council (grant VR 2017-03985), and the Bolin Centre for Climate Research (grant RA6_2019_12). </span></em></p>We found evidence of irreversible ecological breakdown millions of years ago – this time round, we should heed the warning signs.Natasha Barbolini, Senior postdoctoral fellow in palaeoecology, Stockholm UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1372352020-04-28T19:52:12Z2020-04-28T19:52:12ZClimate explained: why higher carbon dioxide levels aren’t good news, even if some plants grow faster<figure><img src="https://images.theconversation.com/files/330586/original/file-20200427-163122-wo4504.jpg?ixlib=rb-1.1.0&rect=29%2C83%2C3956%2C2067&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><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 climate.change@stuff.co.nz</em></p>
<blockquote>
<p><strong>If carbon dioxide levels were to double, how much increase in plant growth would this cause? How much of the world’s deserts would disappear due to plants’ increased drought tolerance in a high carbon dioxide environment?</strong> </p>
</blockquote>
<p>Compared to pre-industrial levels, the concentration of carbon dioxide (CO₂) in the atmosphere will have doubled in about 20 to 30 years, depending on how much CO₂ we emit over the coming years. More CO₂ generally leads to higher rates of photosynthesis and less water consumption in plants. </p>
<p>At first sight, it seems more CO₂ can only be beneficial to plants, but things are a lot more complex than that.</p>
<hr>
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<strong>
Read more:
<a href="https://theconversation.com/climate-explained-why-plants-dont-simply-grow-faster-with-more-carbon-dioxide-in-air-115907">Climate explained: why plants don't simply grow faster with more carbon dioxide in air</a>
</strong>
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<hr>
<p>Let’s look at the first part of the question. </p>
<p>Some plants do grow faster under elevated levels of atmospheric CO₂, but this happens mostly in <a href="https://www.sciencedirect.com/science/article/abs/pii/S0098847215300253">crops</a> and young trees, and generally not in <a href="https://www.nature.com/articles/s41586-020-2128-9?proof=trueHere">mature forests</a>. </p>
<p>Even if plants grew twice as fast under doubled CO₂ levels, it would not mean they strip twice as much CO₂ from the atmosphere. Plants take carbon from the atmosphere as they grow, but that carbon is going straight back via natural decomposition when plants die or when they are harvested and consumed.</p>
<p>At best, you might be <a href="https://theconversation.com/climate-explained-why-your-backyard-lawn-doesnt-help-reduce-carbon-dioxide-in-the-atmosphere-122312">mowing your lawn twice as often</a> or harvesting your plantation forests earlier. </p>
<p>The most important aspect is how long the carbon stays locked away from the atmosphere - and this is where we have to make a clear distinction between increased carbon flux (faster growth) or an increasing carbon pool (<a href="https://science.sciencemag.org/content/355/6321/130.summary">actual carbon sequestration</a>). Your bank account is a useful analogy to illustrate this difference: fluxes are transfers, pools are balances. </p>
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<p>
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<strong>
Read more:
<a href="https://theconversation.com/climate-explained-why-your-backyard-lawn-doesnt-help-reduce-carbon-dioxide-in-the-atmosphere-122312">Climate explained: why your backyard lawn doesn't help reduce carbon dioxide in the atmosphere</a>
</strong>
</em>
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<hr>
<h2>The global carbon budget</h2>
<p>Of the almost 10 billion tonnes (gigatonnes, or Gt) of carbon we emit every year through the burning of fossil fuels, only about half accumulates in the atmosphere. Around a quarter ends up in the ocean (about 2.4 Gt), and the remainder (about 3 Gt) is thought to be <a href="https://www.earth-syst-sci-data.net/10/2141/2018/">taken up by terrestrial plants</a>. </p>
<p>While the ocean and the atmospheric sinks are relatively easy to quantify, the terrestrial sink isn’t. In fact, the 3 Gt can be thought of more as an unaccounted residual. Ultimately, the emitted carbon needs to go somewhere, and if it isn’t the ocean or the atmosphere, it must be the land.</p>
<p>So yes, the terrestrial system takes up a substantial proportion of the carbon we emit, but the attribution of this sink to elevated levels of CO₂ is difficult. This is because many other factors may contribute to the land carbon sink: rising temperature, increased use of fertilisers and atmospheric nitrogen deposition, changed land management (including land abandonment), and changes in species composition. </p>
<p><a href="http://dx.doi.org/10.1038/s41598-017-03818-2">Current estimates</a> assign about a quarter of this land sink to elevated levels of CO₂, but estimates are very uncertain. </p>
<p>In summary, rising CO₂ leads to faster plant growth - sometimes. And this increased growth only partly contributes to sequestering carbon from the atmosphere. The important questions are how long this carbon is locked away from the atmosphere, and how much longer the <a href="https://www.nature.com/articles/s41559-017-0274-8">currently observed land sink will continue</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-explained-how-different-crops-or-trees-help-strip-carbon-dioxide-from-the-air-123590">Climate explained: how different crops or trees help strip carbon dioxide from the air</a>
</strong>
</em>
</p>
<hr>
<p>The second part of the question refers to a side-effect of rising levels of CO₂ in the air: the fact that it enables plants to save water. </p>
<p>Plants regulate the exchange of carbon dioxide and water vapour by opening or closing small pores, called stomata, on the surface of their leaves. Under higher concentrations of CO₂, they can reduce the opening of these pores, and that in turn means they <a href="https://theconversation.com/rising-carbon-dioxide-is-making-the-worlds-plants-more-water-wise-79427">lose less water</a>. </p>
<p>This alleviates drought stress in already dry areas. But again, the issue is more complex because CO₂ is not the only parameter that changes. Dry areas also get warmer, which means that more water evaporates and this often compensates for the water-saving effect.</p>
<p>Overall, rising CO₂ has contributed to some degree to the <a href="https://www.nature.com/articles/nclimate3004">greening of Earth</a>, but it is likely that this trend will not continue under the much more complex combination of global change drivers, particularly in <a href="https://www.sciencedirect.com/science/article/abs/pii/S0098847217301168">arid regions</a>.</p><img src="https://counter.theconversation.com/content/137235/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sebastian Leuzinger receives funding from the Royal Society. </span></em></p>Plants take carbon from the atmosphere as they grow, but it goes straight back when they die or are harvested. There is an important difference between carbon fluxes and actual carbon sequestration.Sebastian Leuzinger, Professor, Auckland University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1170902019-05-21T13:41:12Z2019-05-21T13:41:12ZAgroforestry at 40: how tree-farm science has changed the world<figure><img src="https://images.theconversation.com/files/274632/original/file-20190515-60560-1rp9ynl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Coffee bushes in a shade-grown plantation in the Andes, Ecuador.</span> <span class="attribution"><span class="source">Morley Read/Shutterstock</span></span></figcaption></figure><p>“Agroforestry” – the practice of having trees as part of farms – is as old as agriculture itself. But as a field of scientific enquiry and policy making, it’s now marking its 40th birthday. </p>
<p>In 1978 the International Council for Research in Agro-Forestry <a href="https://www.worldagroforestry.org/about/history">was created</a> to document the use of trees on farms – as a source of income, food and for a healthy environment – and spread information about it. Research gradually became a stronger focus and today it is known as the <a href="http://new.worldagroforestry.org/">World Agroforestry Centre</a>.</p>
<p>It’s an important area of research because <a href="https://www.nature.com/articles/srep29987">more than</a> 40% of the worlds’ agricultural lands have at least 10% tree cover. Because the interactions between trees, soils, crops and livestock can be positive or negative, their relationship must be balanced and understood. </p>
<p>To mark this anniversary my colleagues and I from the World Agroforestry Centre, <a href="http://www.worldagroforestry.org/trees-on-farms">launched a book</a> which takes stock of the science produced and what else needs to be done. A total of 80 authors looked at approaches to agroforestry and how it has contributed to the transformation of rural livelihoods and landscapes. </p>
<p>The key lesson from agroforestry is that tree cover needs to be understood and managed as part of a landscape, harmonising agricultural and forestry policies. This is important because they cover so much land and are vital for the environment and livelihoods. </p>
<p>Having trees on farms has huge benefits for farmers. It could mean more income, a more buffered climate, shelter from winds and rain and, because of tree roots and leaf litter, soil is protected and nurtured. </p>
<p>With the current global push for “climate-smart” policies, agroforestry has presented itself as a way forward. </p>
<h2>The beginnings</h2>
<p>The first section of the book reviews the science of trees, soils and their interactions with crops. </p>
<p>Agroforestry research had to first establish that, contrary to the way agriculture and forestry was presented by policymakers and in policy as separate worlds, it exists. </p>
<p>There’s a relationship between trees and crops that happens in many places, in many forms, involving <a href="http://www.worldagroforestry.org/downloads/Publications/PDFS/BC19009.pdf">at least</a> 600 species of trees worldwide. </p>
<p>But because agriculture and forestry were treated separately in policies, there were challenges in how trees on farms should be managed. For instance, farmers with a lot of trees on their land often got caught in forestry rules in terms of how they could use them. </p>
<p>An example of this was that many francophone African countries inherited laws at independence which declared that <a href="https://www.theguardian.com/world/2018/aug/16/regreening-niger-how-magical-gaos-transformed-land">all trees</a> belonged to the state. This meant farmers started to remove them where they could, because trees compete with crops for resources like water, leading to soil degradation. </p>
<p>The policy only changed after farmers in Niger <a href="http://www.worldagroforestry.org/book-chapter/zinder-farmer-managed-natural-regeneration-sahelian-parklands-niger">found ways</a> to circumvent the rules and show that farmers could own trees and land would regenerate as a result. Other countries in the Sahel followed suit.</p>
<p>Policymakers eventually began to change their views when they understood how farmers, trees, forests and water interacted at the landscape scale.</p>
<h2>Transformations</h2>
<p>The second section of the book looks at six landscapes around the world where agroforestry actions by farmers, supported by scientists, helped local transformations to happen. </p>
<p>One example, where local projects inspired change elsewhere, was in <a href="http://www.worldagroforestry.org/downloads/Publications/PDFS/BC19014.pdf">Shinyanga</a>, northern Tanzania. Drought, overgrazing and political changes had led to forest loss and land damage. A project – between government, the World Agroforestry Centre, International Union for Conservation of Nature and local partners – <a href="http://www.worldagroforestry.org/downloads/Publications/PDFS/BC19014.pdf">successfully restored</a> 370,000 hectares of land. </p>
<p>Key lessons from this project were to use land practices that contributed to livelihoods (like planting trees that would bear fruits) – and linking planning to national policies. </p>
<p>Examples like this began to show policymakers that bridges are needed between forest-based institutions and agricultural ones. It also showed how agroforestry can contribute to current global issues of focus – like climate change and the <a href="https://sustainabledevelopment.un.org/?menu=1300">Sustainable Development Goals</a>. For example, <a href="http://www.worldagroforestry.org/downloads/Publications/PDFS/BC19023.pdf">growing plants</a> with oil-rich seeds, like <em>Jatropha curcas</em> a flowering plant native to the American tropics, which can produce biofuel (fuel produced from living matter). Or growing certain trees in areas because they <a href="http://www.worldagroforestry.org/downloads/Publications/PDFS/BC19024.pdf">can help</a> manage water flows. </p>
<h2>The future</h2>
<p>The final part of the book suggests a way forward for the communication between science and policymakers. </p>
<p>Scientific knowledge can help in four stages of a policy process: </p>
<ul>
<li><p>Exploring new issues and sorting out which ones deserve to be on the agenda for public discussions</p></li>
<li><p>Identify the underlying causes that need to be addressed in policy commitments</p></li>
<li><p>Clarify the trade-offs that any policy implementation will face, and ways to make these manageable</p></li>
<li><p>Setting up ways to monitor change, so that there still is space for innovative solutions. </p></li>
</ul>
<p>The book highlights that land use policies must connect local action with global concerns. It demonstrates the potential that agroforestry has for the Sustainable Development Goal agenda.</p><img src="https://counter.theconversation.com/content/117090/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>ICRAF, the employer of Meine van Noordwijk, receives funding from many internatioonal government and non-government sources. He is affiliated with Wageningen University and currently serves on an effort by the Intergovernment Panel for Biodiversity and Ecosystem Services (IPBES). </span></em></p>Because the interactions between trees, soils, crops and livestock can be positive or negative, their relationship must be balanced and understood.Meine van Noordwijk, Distinguished Research Fellow, Center for International Forestry Research – World Agroforestry (CIFOR-ICRAF)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1027452018-09-06T18:51:06Z2018-09-06T18:51:06ZMassive solar and wind farms could bring vegetation back to the Sahara<figure><img src="https://images.theconversation.com/files/235240/original/file-20180906-190642-14gnoyr.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">Juanjo Tugores / shutterstock</span></span></figcaption></figure><p>Switching from fossil fuels to renewable energy is an important and necessary step towards averting climate change. However, in our efforts to go green, we also need to be mindful of other consequences, both intended and unintended – and that includes how a mass deployment of renewable technology might affect its surrounding climate. </p>
<p>What if the Sahara desert was turned into a giant solar and wind farm, for instance? This is the topic of new research published in <a href="http://dx.doi.org/10.1126/science.aar5629">Science</a> by Yan Li and colleagues. They found that all those hypothetical wind turbines and solar panels would make their immediate surroundings both warmer and rainier, and could turn parts of the Sahara green for the first time in <a href="https://www.smithsonianmag.com/science-nature/what-really-turned-sahara-desert-green-oasis-wasteland-180962668/">at least 4,500 years</a>. </p>
<p>The scientists behind the research looked at the maximum amount of solar and wind energy that could be generated in the Sahara desert and the transition region to its south, the Sahel. The two regions were picked as they are relatively plausible sites for such an enormous roll-out of renewable energy, being fairly near to substantial demand from Europe and the Middle East, while having limited other demands on the land. Both have substantial potential resources of wind and solar energy. Li and colleagues also suggest that The Sahel, in particular, could also benefit from economic development and more energy for desalination, providing water for cities and agriculture. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/235242/original/file-20180906-190656-jgzyu3.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/235242/original/file-20180906-190656-jgzyu3.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/235242/original/file-20180906-190656-jgzyu3.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/235242/original/file-20180906-190656-jgzyu3.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/235242/original/file-20180906-190656-jgzyu3.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/235242/original/file-20180906-190656-jgzyu3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/235242/original/file-20180906-190656-jgzyu3.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/235242/original/file-20180906-190656-jgzyu3.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"></a>
<figcaption>
<span class="caption">Africa has the greatest solar resource of any continent – by far.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:SolarGIS-Solar-map-Africa-and-Middle-East-en.png">SolarGIS</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>As the two regions are so large, the solar and wind farms that were simulated in this study are the size of entire countries – 38 times larger than the UK. They would be vastly bigger than any existing solar and wind farms, and could provide up to four times as much energy as is currently consumed globally. </p>
<p>This would prompt quite significant changes in the local environment – massive wind farms would raise temperatures by around 2°C for instance, similar to the amount of global warming we are concerned about. Solar would cause a smaller temperature change, around 1°C. </p>
<p>Precipitation increases of 0.25 mm per day associated with wind farms sound more modest, yet this would be almost double the previous amount of rainfall. Again, the effect associated with solar parks was smaller – an increase of 0.13 mm/day – but still significant when added up over a year. </p>
<h2>Why turbines and panels mean warmth and rain</h2>
<p>Wind farms largely cause temperature increases because their turbine blades bring warmer air down to the surface, especially at night. This has been observed in <a href="http://www.pnas.org/content/107/42/17899">field studies</a> and using <a href="https://www.nature.com/articles/nclimate1505">remote sensing</a>. They have also been shown to <a href="http://iopscience.iop.org/article/10.1088/1748-9326/11/4/044024">increase moisture in the air</a>.</p>
<p>Solar panels mean more solar radiation is absorbed and less of the sun’s energy is reflected back into space. This causes the land surface to warm up. Several studies have shown this, including one which showed that the effect of warming caused by fossil fuels, via carbon emissions, was <a href="https://pubs.acs.org/doi/abs/10.1021/es801747c">30 times greater</a> than the warming caused by solar photovoltaics absorbing more solar radiation. However, temperature effects may vary <a href="http://iopscience.iop.org/article/10.1088/1748-9326/11/7/074016">within the solar park and with season</a>.</p>
<p>In the Sahara simulation, extra rainfall happens because wind turbines represent an obstacle to free-flowing air, slowing it down and reducing the <a href="https://www.metoffice.gov.uk/learning/atmosphere/coriolis-effect">effect of the Earth spinning</a> on air flow. This lowers the air pressure, and the difference in pressure between the Sahara and surrounding areas causes wind to flow there. When the air meets, or converges, in the Sahara it has nowhere else to go but up. As the air rises, water vapour in it condenses and rain drops form. </p>
<p>For solar, the process is slightly different: warmer air, heated by the panels, simply rises. However, this also promotes low pressure, causing air to flow there, converge and rise. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/235241/original/file-20180906-190650-2f86mk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/235241/original/file-20180906-190650-2f86mk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/235241/original/file-20180906-190650-2f86mk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=575&fit=crop&dpr=1 600w, https://images.theconversation.com/files/235241/original/file-20180906-190650-2f86mk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=575&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/235241/original/file-20180906-190650-2f86mk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=575&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/235241/original/file-20180906-190650-2f86mk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=723&fit=crop&dpr=1 754w, https://images.theconversation.com/files/235241/original/file-20180906-190650-2f86mk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=723&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/235241/original/file-20180906-190650-2f86mk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=723&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-scale wind and solar would mean more new rain in some areas than others.</span>
<span class="attribution"><span class="source">Eviatar Bach</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>More rainfall also means more vegetation. This increases surface roughness, as with wind turbines, and causes more solar radiation to be absorbed, as with solar panels. This reinforcing cycle is known as a “climate feedback” and incorporating these vegetation feedbacks is a novel aspect of the research by Li and colleagues.</p>
<h2>Time to make it a reality?</h2>
<p>Not quite. Decisions aren’t made in response to environmental impacts alone – if this was the case we’d have already ditched fossil fuels. It’s certainly true that developing a mega renewable energy site across the Sahara and the Sahel would be a game-changer, but there are lots of other factors to consider first. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/235261/original/file-20180906-190665-qwxic6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/235261/original/file-20180906-190665-qwxic6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/235261/original/file-20180906-190665-qwxic6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=289&fit=crop&dpr=1 600w, https://images.theconversation.com/files/235261/original/file-20180906-190665-qwxic6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=289&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/235261/original/file-20180906-190665-qwxic6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=289&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/235261/original/file-20180906-190665-qwxic6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=363&fit=crop&dpr=1 754w, https://images.theconversation.com/files/235261/original/file-20180906-190665-qwxic6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=363&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/235261/original/file-20180906-190665-qwxic6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=363&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In the Sahara – but still someone’s home.</span>
<span class="attribution"><span class="source">meunierd / shutterstock</span></span>
</figcaption>
</figure>
<p>These areas may be sparsely populated but people do live there, their livelihoods are there, and the landscapes are of cultural value to them. Can the land really be “grabbed” to supply energy to Europe and the Middle East?</p>
<p>Coherent and stable energy policies are challenging enough within an individual nation, let alone between nations with all the potential political implications and energy security issues. Though mass amounts of cheap Saharan energy sounds like a great thing, it is not clear it would be a secure enough investment for the economics to add up.</p>
<p>It’s also hard to tell what this would mean for desertification, which is caused by poor land management, such as overgrazing, as well as by the climate. The changes to rainfall looked at in this study are regional, not global, and once the wind and solar farms were taken away their effects would disappear and the land could revert back to its previous state.</p>
<p>Overall, this is an interesting and important piece of research, highlighting the need to be mindful of unintended consequences, be these positive or negative, of the energy transition. Integrating these findings with other social, economic, environmental and technical considerations is essential to ensure we don’t leap from the frying pan into the fire.</p><img src="https://counter.theconversation.com/content/102745/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alona Armstrong receives funding from NERC and EPSRC to study the environmental impacts of renewable energy infrastructure.</span></em></p>Scientists have modelled the effects of huge hypothetical energy projects in the desert.Alona Armstrong, Senior lecturer, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/985682018-07-05T20:54:41Z2018-07-05T20:54:41ZHow to fight desertification and drought at home and away<figure><img src="https://images.theconversation.com/files/226380/original/file-20180705-122268-1yziwnv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A farmer plows a dry and dusty cotton field near Phoenix, Ariz., while a drought affects the Southwest.</span> <span class="attribution"><span class="source">(AP Photo/Ross D. Franklin)</span></span></figcaption></figure><p>A growing human population and runaway consumption are putting <a href="https://wad.jrc.ec.europa.eu/">unsustainable pressures</a> on the natural resources we depend on for survival. Our misuse and abuse of land and water is changing fertile land into deserts. </p>
<p>The word “desertification” conjures up images of the spread of existing deserts, with tall dunes spilling into villages and farmer’s fields. But it is actually <a href="https://www.researchgate.net/publication/310750021_Mapping_desertification_constraints_and_challenges?enrichId=rgreq-67d9a2b9463fb272a95a5b0cbde927df-XXX&enrichSource=Y292ZXJQYWdlOzMxMDc1MDAyMTtBUzo1MjYwODIyMzY1MjI0OTZAMTUwMjQzOTE4NzE2Mg%3D%3D&el=1_x_3&_esc=publicationCoverPdf">a term that describes the way land can be transformed</a> by climate variation and human activities, including deforestation, overgrazing (which causes erosion), the cultivation of unsuitable land and other poor land-use management decisions. </p>
<p>We see this now in southern Africa, which has already lost at least <a href="https://www.researchgate.net/publication/229571074_An_overview_of_environmental_issues_in_Southern_Africa?_esc=publicationCoverPdf&el=1_x_2&enrichId=rgreq-f66703e9002784161a8ae55da3316e2b-XXX&enrichSource=Y292ZXJQYWdlOzIyOTU3MTA3NDtBUzoxMDIyMDQyNTgxMjc4ODNAMTQwMTM3ODgwMjc3Ng%3D%3D">25 per cent</a> of its soil fertility. </p>
<p>But not only developing countries are at risk. <a href="https://www.sciencedirect.com/science/article/pii/S1462901115300654">Almost 1 billion tonnes of soil</a> is lost every year because of erosion resulting from poor land management in Europe alone. </p>
<p>Desertification is one of the biggest environmental problems facing humanity, and has already affected <a href="https://www.theguardian.com/environment/2018/mar/26/land-degradation-is-undermining-human-wellbeing-un-report-warns">over 40 per cent</a> of the world’s population — 3.2 billion people. </p>
<p>Given that climate change could cause <a href="https://www.carbonbrief.org/climate-change-could-cause-more-severe-droughts-98-per-cent-european-cities">more frequent droughts</a> and that population growth puts more pressure on natural resources, land degradation is an increasing global threat to food security, a contributor to poverty and a <a href="https://wad.jrc.ec.europa.eu/">barrier to achieving the United Nation’s Sustainable Development Goals</a>. </p>
<p>It is clear that desertification is a problem of global proportions, requiring a unified strategy among all countries. If action is not taken now, desertification will accelerate, resulting in further migration and conflict.</p>
<h2>Seeing the threat</h2>
<p>Not all areas are equally at risk of desertification. Drylands, like those in the Karoo of South Africa and the prairies of Canada, are regions where evapotranspiration (the transfer of water from land and plants to the atmosphere) far exceeds precipitation. </p>
<p>Under natural conditions, drylands are characterised by slow cycles of changing climate and vegetation, moving from one stable state to another. More frequent and severe droughts and human disturbances, such as agriculture, grazing and fire, cause more <a href="https://www.nature.com/articles/s41598-017-04341-0">abrupt shifts</a> that can be irreversible.</p>
<p>The threat of land degradation is so widely recognized that the UN established the <a href="https://www.unccd.int/">Convention to Combat Desertification</a> (UNCCD) nearly 25 years ago, in 1994. It is a legally binding agreement between the partner nations to work together to achieve sustainable land management.</p>
<p>All member countries of the UNCCD recently agreed to <a href="https://www.cpj.ca/canada-re-joins-un-convention-combat-desertification">fight desertification</a> and <a href="https://www.unccd.int/actions/achieving-land-degradation-neutrality">restore degraded land</a> by 2030. On June 17, Ecuador hosted the World Day to Combat Desertification, under the slogan “<a href="https://www.unccd.int/news-events/2018-world-day-combat-desertification-2018wdcd">Land has true value – Invest in it</a>,” and used the occasion to showcase the use of sustainable land management in developing the country’s bio-economy.</p>
<h2>A tentative pledge</h2>
<p>Despite its initial commitment to combat desertification, <a href="https://www.thestar.com/news/canada/2013/03/28/canada_saw_bureaucracy_and_inefficiency_in_un_convention_on_deserts.html">Canada withdrew from the UNCCD in 2013</a>. The reasons were unclear, but it may have been because membership was seen as too costly, without obvious benefits for the environment. The departure left Canada as the only country not party to the agreement. </p>
<p>However, <a href="https://www.siskinds.com/envirolaw/canada-rejoins-united-nations-convention-combat-desertification/">Canada rejoined last year</a>, acknowledging the link between desertification and many of Canada’s development priorities. The factors driving land degradation are interconnected and include population growth and migration, climate change and biodiversity loss. </p>
<p>Current rates of global land degradation are in the order of <a href="https://reliefweb.int/report/world/high-price-desertification-23-hectares-land-minute">12 million hectares per year</a>. And yet <a href="http://www.fao.org/fileadmin/templates/wsfs/docs/Issues_papers/HLEF2050_Global_Agriculture.pdf">food production must increase by up to 70 per cent by 2050 to feed the projected global population of 9.1 billion people</a>. Current land-management practices are clearly unsustainable. </p>
<p>The threatened area is so large that halting land degradation and <a href="https://static1.squarespace.com/static/5694c48bd82d5e9597570999/t/5996c27ef7e0aba0564ee740/1503052415896/Scaling+Up+SLM_R_Thomas+et+al.pdf">scaling up solutions</a> — from farms and villages to watersheds and continents — requires globally coordinated solutions. By rejoining the UNCCD, Canada can take its rightful place within a coordinated global effort to combat desertification — and strengthen its own efforts nationally. </p>
<h2>Why Canada should care</h2>
<p>Canada has already cooperated on a regional level with other countries to combat drought and minimize the impacts of reduced agricultural productivity, wildfires and water shortages. </p>
<p>In 2016, for example, when droughts hounded North America, <a href="https://globalnews.ca/news/3138183/fort-mcmurray-wildfire-named-canadas-news-story-of-2016/">burning</a> Fort McMurray, Alta. and adding to <a href="http://www.latimes.com/opinion/op-ed/la-oe-famiglietti-chronic-water-scarcity-20160417-story.html">California’s long-running water shortage</a>, Canada cooperated with the <a href="https://www.ars.usda.gov/research/publications/publication/?seqNo115=336751">United States and Mexico</a> to minimize their impacts. The resulting North American Climate Services Partnership (NACSP) facilitated an early drought forecasting system and drought impact assessments.</p>
<p>In addition, Canada faces its own land degradation challenges. Most people associate dryland regions with a hot and dry climate. However, large parts of the Canadian Prairie provinces — Alberta, Saskatchewan and Manitoba — <a href="https://www.cpj.ca/canada-re-joins-un-convention-combat-desertification">can be classified as drylands</a>. They are also enormously important agricultural areas, accounting for 60 per cent of the cropland and 80 per cent of the rangeland in Canada. </p>
<p>The Prairies expect to see <a href="https://link.springer.com/article/10.1007/s10113-016-1078-0">longer and more intense periods of drought interspersed with major flooding</a> with future climate change. And although North America is one of five regions identified by the UN as <a href="http://www.pbl.nl/en/publications/exploring-future-changes-in-land-use">facing relatively fewer challenges related to land</a> compared to the countries most at risk, the region does face significant water stress challenges.</p>
<h2>Way forward</h2>
<p>The Paris Agreement recognized “<a href="https://www.cpj.ca/canada-re-joins-un-convention-combat-desertification">safeguarding food security</a>” as an important priority for climate change adaptation, which goes hand-in-hand with combating desertification. </p>
<p>The agricultural sector will play an important role in mitigating the impacts of climate change — and fighting land degradation. It can protect against drought, flooding, landslides and erosion, while maintaining natural vegetation, which helps store carbon in the soil. </p>
<p>But agricultural production will also <a href="https://static1.squarespace.com/static/5694c48bd82d5e9597570999/t/5996c27ef7e0aba0564ee740/1503052415896/Scaling+Up+SLM_R_Thomas+et+al.pdf">have to become more efficient</a>. It will need to adapt to periods of lower water availability and take measures to preserve fertile soil. </p>
<p>We must also look to how we manage our water resources to help agriculture adapt to climate change and stop desertification. </p>
<p>The <a href="https://gwf.usask.ca/impc/index.php">University of Saskatchewan is currently developing tools</a> that can be used by government and in research to predict and manage the water flow and water quality of Canada’s large river basins. This will allow water to be managed at the scale of entire river basins and help determine how industry, agriculture and mining can fairly share this limited resource.</p>
<p>Canada has, for now, recognized the link between desertification and many of its development priorities, including agriculture, security, water and renewable energy. But we need to ensure the Canadian government remains committed to combating drought and desertification here — and in the rest of the world.</p><img src="https://counter.theconversation.com/content/98568/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Slaughter is supported by the Global Water Futures (GWF) programme in his capacity as a Visiting Professor within the Global Institute for Water Security, University of Saskatchewan. Dr Slaughter has previously received funding from the Water Research Commission, Pretoria, South Africa.</span></em></p>Desertification is a problem of global proportions. If action isn’t taken now, it will accelerate and fuel further migration and conflict.Andrew Slaughter, Visiting professor, University of SaskatchewanLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/941002018-03-28T08:47:43Z2018-03-28T08:47:43ZOn dangerous ground: land degradation is turning soils into deserts<p>If any of us still has the slightest doubt that we are facing an ecological crisis on an unprecedented scale, then a new <a href="https://www.ipbes.net/news/media-release-worsening-worldwide-land-degradation-now-%E2%80%98critical%E2%80%99-undermining-well-being-32">report on land degradation</a>, released this week by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (<a href="https://www.ipbes.net/">IPBES</a>), provides yet another piece of evidence.</p>
<p><a href="https://sustainabledevelopment.un.org/topics/desertificationlanddegradationanddrought">Land degradation</a> can take many forms, but always entails a serious disruption of a healthy balance between <a href="http://www.pbl.nl/sites/default/files/cms/publicaties/pbl-2017-exploring-future-changes-in-land-use-and-land-condition-2076.pdf">five key ecosystem functions</a>. These are: food production; fibre provision; microclimate regulation; water retention; and carbon storage.</p>
<p>Its impacts can be far-reaching, including loss of soil fertility, destruction of species habitat and biodiversity, soil erosion, and excessive nutrient runoff into lakes. </p>
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<a href="https://theconversation.com/the-immense-challenge-of-desertification-in-sub-saharan-africa-84439">The immense challenge of desertification in sub-Saharan Africa</a>
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<p>Land degradation also has serious knock-on effects for humans, such as malnutrition, disease, forced migration, cultural damage, and even war. </p>
<p>At its worst, land degradation can result in the desertification or abandonment of land (or both). Protracted drought and loss of fertile land may have been contributing factors in the wars in <a href="https://postconflict.unep.ch/publications/UNEP_Sudan_synthesis_E.pdf">Sudan</a> and <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1421533112">Syria</a>.</p>
<p>According to the new report, 43% of world populations live in regions affected by land degradation. By 2050, the report estimates, 4 billion people will be living in drylands. These are defined by the United Nations as land with an “aridity ratio” of less than 0.65, meaning that the amount of water lost far outweighs the amount received in precipitation. </p>
<p>Such areas are highly vulnerable to food and water insecurity, especially in sub-Saharan Africa and the Middle East.</p>
<h2>A global threat</h2>
<p>It would be wrong to infer that land degradation is purely a problem for developing countries. Overall, land is generally more degraded in the developed world – as shown, for example, by <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/fes3.96">greater declines in soil organic carbon content</a>, a measure of soil health. However, in richer nations the rate of degradation has slowed, and people in these regions are generally less vulnerable to its effects.</p>
<p>It is in sub-Saharan Africa, Asia and South and Central America that the problem is growing most rapidly. But climate change, especially where droughts and forest fires are becoming more frequent, can cause land degradation even in affluent places such as California and Australia. </p>
<p>What’s more, a decline in the overall availability of agricultural land is bound to affect food prices globally. By 2050, the report states, humans will have transformed almost every part of the planet, apart from uninhabitable stretches such as deserts, mountains, tundra and polar regions. </p>
<p>Perhaps most chillingly, the report predicts that the combined effects of land degradation and climate change will have displaced between 50 million and 700 million people by 2050, potentially triggering <a href="https://www.unicef.org/socialpolicy/files/Economics_and_Violent_Conflict.pdf">conflict</a> over <a href="https://wedocs.unep.org/bitstream/handle/20.500.11822/22269/Frontiers_2017_CH6_EN.pdf?sequence=1&isAllowed=y">disputed land</a>.</p>
<p>Some of this migration will inevitably be across international borders – how much is impossible to tell. While the impacts on migrants are almost always devastating, the ripple effects, as we have seen recently with the Syrian war, can spread far and wide, affecting electoral outcomes, border controls and social security systems throughout the world.</p>
<h2>Globalised causes</h2>
<p>The two most significant <a href="http://www.pbl.nl/sites/default/files/cms/publicaties/pbl-2017-exploring-future-changes-in-land-use-and-land-condition-2076.pdf">direct causes</a> of land degradation are the conversion of native vegetation into crop and grazing lands, and unsustainable land-management practices. Other factors include the effects of climate change and loss of land to urbanisation, infrastructure and mining. </p>
<p>However, the underlying driver of all these changes is rising per-capita demand from growing populations for protein, fibre and bioenergy. This in turn leads to more demand for land and further encroachment into areas with marginal soils. </p>
<p>Market deregulation, which has been a <a href="http://hubrural.org/IMG/pdf/unisfera_from_boom_to_dust.pdf">global trend</a> since the 1980s, can lead to the destruction of sustainable land management practices in favour of <a href="https://digitalcommons.law.seattleu.edu/cgi/viewcontent.cgi?article=1569&context=faculty">monocultures</a>, and can encourage a race to the bottom as far as environmental protection is concerned. The vast geographical distance between demand for consumer goods and the land needed to produce them – between, in other words, the cause of land degradation and its effect – makes it much harder to address the problem politically. </p>
<p>Sadly, the timid history of attempts to create global governance regimes over the past century – from human rights, to conflict prevention, arms control, social protections and environmental treaties – has seen more failures than successes. </p>
<p>On the positive side, success stories in land management are well documented: agroforestry, conservation agriculture, soil fertility management, regeneration and water conservation. In fact, the new report states that the economic case for land restoration is strong, with benefits averaging ten times the costs, even when looking at very different types of lands and communities of flora and fauna. A common feature of many of these success stories is major involvement by indigenous populations and local farmers. </p>
<p>And yet these achievements remain far short of the scope of the problem. Significant obstacles remain – including, according to the report, increasing demand for land, lack of awareness of the extent of land degradation, fragmented decision-making within and between countries, and increased costs of restoration as time goes by. </p>
<p>On the other hand, the report’s authors emphasise that a host of existing multilateral agreements, including conventions on <a href="https://www2.unccd.int/">desertification</a>, <a href="http://unfccc.int/2860.php">climate change</a>, <a href="https://www.cbd.int/">biodiversity</a> and <a href="https://www.ramsar.org/">wetlands</a>, provide a strong platform for combating land degradation. However, whether these agreements will be successful in overcoming the obstacles mentioned above remains to be seen.</p>
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Read more:
<a href="https://theconversation.com/if-the-worlds-soils-keep-drying-out-thats-bad-news-for-microbes-and-people-53937">If the world's soils keep drying out that's bad news for microbes (and people)</a>
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<p>What can we do as citizens, especially those of us who live in cities and have little direct interaction with the land? The most obvious action is to eat less meat and, more generally, to inform ourselves about the sources and impacts of the food we buy – including its packaging, fuel and transport. </p>
<p>But the problem is not just about individual choices, important as these are. Underlying systemic causes need to be addressed, including deregulated international trading systems, lack of protection for local communities powerless to resist global market forces, ideologies of unfettered growth and perverse incentives for more consumption. </p>
<p>Arguably, what is needed is a broadening of the active scope of national politics, from an almost exclusive concern with short-term economic well-being to the making of global futures. Next time you meet your local representative, ask them what they are doing to protect the interests of your children and grandchildren. Or, even better, inform yourself, talk to others about it, form your own opinion about what should be done, then try to make it happen.</p><img src="https://counter.theconversation.com/content/94100/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Abbas El-Zein receives funding from the Australian Research Council (ARC). </span></em></p>A new international report makes for bleak reading on the state of the world’s soils. It predicts that land degradation will displace up to 700 million people worldwide by mid-century.Abbas El-Zein, Professor of Environmental Engineering, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/786272017-06-18T09:22:46Z2017-06-18T09:22:46ZAfrica’s got plans for a Great Green Wall: why the idea needs a rethink<figure><img src="https://images.theconversation.com/files/173386/original/file-20170612-10220-1jrelzo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">By the end of the 1990s, the idea of encroaching deserts had become difficult to defend.</span> <span class="attribution"><span class="source">IFRC/Flickr</span></span></figcaption></figure><p>Africa’s Great Green Wall, or more formally <a href="http://www.greatgreenwallinitiative.org/">The Great Green Wall for the Sahara and the Sahel Initiative</a>, is the intriguing but misleading name of an enormously ambitious and worthwhile initiative to improve life and resilience in the drylands that surround the Sahara. </p>
<p>The idea of a Great Green Wall has come a long way since its inception. Its origin goes back to colonial times. In 1927, the French colonial forester Louis Lavauden <a href="https://link.springer.com/chapter/10.1007/978-3-642-16014-1_8">coined the word desertification</a> to suggest that deserts are spreading due to deforestation, overgrazing and arid land degradation. In 1952 the English forester Richard St. Barbe Baker suggested that a <a href="https://wilmetteinstitute.org/the-man-of-the-trees-and-the-great-green-wall-a-bahais-environmental-legacy-for-the-ages/">“green front”</a> in the form of a 50km wide barrier of trees be erected to contain the spreading desert.</p>
<p>Droughts in the Horn of Africa and the Sahel from the 1970s onwards gave wings to the idea, and in 2007 the African Union approved the Great Green Wall Initiative. Many perceived it as a plan to build an almost 8,000km long, 15km wide, wall of trees across the African continent – from Senegal in the west to Djibouti in the east. </p>
<p>This plan faced a great deal of criticism. It led to a clearer vision being endorsed under the same name five years later when the African Ministerial Conference on Environment adopted a <a href="http://www.greatgreenwallinitiative.org/sites/default/files/publications/harmonized_strategy_GGWSSI-EN_.pdf">harmonised regional strategy</a>.</p>
<p>Can the vision ever come to fruition? </p>
<p>Only if there’s a ten-fold (at least) increase in pace so that the progress on the ground becomes consistent with lofty political ambitions. Sadly, the wall suffers from a major mismatch between ambition and effort. But that’s not to say it should be ditched. </p>
<h2>Why did the vision change?</h2>
<p><a href="http://www.csf-desertification.eu/combating-desertification/item/the-african-great-green-wall-project">Critics argue</a> that a desert is a healthy, natural ecosystem that shouldn’t be thought of as a disease. Nor, they argue, is it spreading like a disease. In fact, by the end of the 1990s, the idea of encroaching deserts had become <a href="https://www.iied.org/end-desertification">difficult to defend</a> against scientific evidence that climate variability was to blame. </p>
<p>Critics <a href="http://www.csf-desertification.eu/combating-desertification/item/the-african-great-green-wall-project">have also pointed out</a> that the vision of a barrier is counter-productive to the development objective as it draws attention to the perimeter of the land rather than to the land itself. To boost food security and support local communities it is better to focus on the wide field rather than its narrow edge. The development objective is important – an <a href="http://www.un.org/sustainabledevelopment/blog/2016/11/great-green-wall-initiative-offers-unique-opportunity-to-combat-climate-change-in-africa-un-agency/">estimated 232 million</a> people live in the general area of the Great Green Wall. </p>
<p>This led to the clarified vision keeping the wall in name, but it has been bent almost beyond recognition.</p>
<p>The wall is no longer seen as a narrow band of trees along the southern edge of the Sahara. The vision is now to surround the Sahara with a wide belt of vegetation – trees and bushes greening and protecting an agricultural landscape. The new vision engages all the countries surrounding it, including Algeria and others in North Africa, not just the 11 original sub-Saharan countries of the Sahel.</p>
<p>Thus, the Great Green Wall is no longer a wall. Nor is it great – not yet anyway.</p>
<h2>Unrealistic ambitions</h2>
<p>A simple analysis gives a clear indication of how difficult it will be to realise the Great Green Wall within agreed timelines. </p>
<p>A recent <a href="http://www.un.org/sustainabledevelopment/blog/2016/11/great-green-wall-initiative-offers-unique-opportunity-to-combat-climate-change-in-africa-un-agency/">analysis</a> by the Food and Agriculture Organisation suggests that 128 million hectares have a tree cover below the “better half” of comparable landscapes in the two aridity zones that straddle the 400 mm rainfall line around the Sahara. </p>
<p>If one assumes that half of this (65 million hectares, or 8% of the total area in these aridity zones) needs intervention, and that the United Nations’ <a href="http://www.un.org/sustainabledevelopment/development-agenda/">2030 Agenda for Sustainable Development</a> sets the target date for completion, then the Great Green Wall initiative should be treating an average of 5 million hectares per year (10 million hectares is the ambition to bring all lands up to the level of the better half). A less ambitious target date would be set by the African Union’s <a href="http://www.au.int/web/en/agenda2063">Agenda 2063</a> but even then an average treatment of 2 million hectares per year would be needed. </p>
<p>The actual intervention area is not known but is likely to be far less, no more than 200,000 hectares per year and probably less. At this pace, a century is an optimistic prediction of the time it will take to complete the Wall.</p>
<p>A massive increase in speed –- at least ten-fold –- is required if the Wall is to become great in our lifetime. More resources will clearly be needed but a ten-fold increase is unlikely. What to do?</p>
<h2>Re-greening options</h2>
<p>Many people assume that the wall can only be built only by planting trees. But tree planting is not always needed. Some of the less dry lands can be treated by techniques that rely on the capacity of the land to regreen itself – its ecological memory. </p>
<p>Floods and animals move seeds to places where they can sprout and root systems of former trees are sometimes capable of producing new shoots. Sprouting roots could live as the roots are already established – unlike newly planted seedlings. These could rapidly re-green a landscape, reducing the need for tree planting, as long as farmers protect them from fire and cattle. </p>
<p>This technique – known as farmer-managed natural regeneration – has proven to produce <a href="http://onlinelibrary.wiley.com/doi/10.1111/btp.12390/full">good results at low cost</a> in areas where the ecological memory is sufficient for sprouts to come up by themselves and where farmers have the right to use the trees once they get big. The potential to <a href="https://www.wri.org/sites/default/files/scaling-regreening-six-steps-success.pdf">scale it up</a> is significant.</p>
<p>But farmer-managed natural regeneration will not work everywhere. Other methods are needed too, such as digging half-moons (to capture water) and planting seedlings. Doing a better job of applying the right method to the right place may be the quickest and most feasible way to speed the making of the Great Green Wall.</p><img src="https://counter.theconversation.com/content/78627/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lars Laestadius is affiliated as a consultant with the United Nations Food and Agriculture Organisation. </span></em></p>Africa’s great green wall suffers from a major mismatch between ambition and effort. But that’s not to say it should be ditched altogether.Lars Laestadius, Adjunct Lecturer, Swedish University of Agricultural SciencesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/784232017-06-08T10:47:45Z2017-06-08T10:47:45ZChad is the country most vulnerable to climate change – here’s why<figure><img src="https://images.theconversation.com/files/172291/original/file-20170605-16888-1v7xt5o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/eu_echo/8022587028/">European Commission DG ECHO / flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Of the 186 countries assessed in a recent survey of climate vulnerability, <a href="http://reliefweb.int/sites/reliefweb.int/files/resources/Verisk_Maplecroft_Climate_Change_Vulnerability_Index_2016_Infographic.pdf">Chad was rated most in peril</a>. A combination of high poverty, frequent conflicts, and the risk of both droughts and floods means the central African nation is bottom of the list, just below Bangladesh and some way behind Norway, the country least vulnerable to climate change.</p>
<p>So why Chad? For a start, it is one of the poorest countries in the world. Around 87% of Chadians are classified as poor, according to the <a href="http://www.dataforall.org/dashboard/ophi/index.php/mpi/download_brief_files/TCD">Multidimentional Poverty Index</a>, which factors in health, education and living standards. That’s the fourth highest rate in the world. The percentage who are “destitute” (63%), the most extreme category of poverty, is also the fourth highest in the world.</p>
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<span class="caption">The landlocked country stretches from the Sahara to Cameroon.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Chad_in_Africa_(-mini_map_-rivers).svg">TUBS / wiki</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<p>This is exacerbated by the fact that the country has been in civil war or conflict for 35 out of the 57 years since it gained independence from France. </p>
<p>Any poor or conflict-prone country will always be vulnerable, but Chad’s geography means climate change is a particular risk. Chad is bigger than many Westerners may realise. At 1.28m km² it’s larger than Nigeria and twice the size of Texas. Around 90% of its 10m people live in the southern half of the country, as most of the northern half extends well into the Sahara desert. </p>
<p>Most Chadians base their livelihoods on subsistence farming and livestock rearing. The semi-arid rangelands of the Sahel, in the north of the country, provide pasture for livestock during the rainy season, while the fertile agricultural fields in the south produce most of the cash and food crops. When the dry season begins, pastoralists <a href="https://books.google.se/books?id=_6YWDAAAQBAJ&lpg=PP1&pg=PT77#v=onepage&q&f=false">move their herds south</a> to feed on the leftovers of the agricultural harvest.</p>
<h2>Chad’s changing climate</h2>
<p>Since the mid-20th century, <a href="http://chg.ucsb.edu/gallery/chad/images/index.html">temperatures in Chad have been increasing while rainfall is decreasing</a>. Ninety percent of the country’s largest lake, Lake Chad, has disappeared over the past 50 years due to a combination of droughts and increasing withdrawals for irrigation. Climate studies project things will get increasingly hot and arid <a href="https://link.springer.com/article/10.1007/s10584-015-1522-z">throughout the 21st century</a>, which means lower crop yields, worse pasture, and a harder life for anyone dependent on Lake Chad.</p>
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<img alt="" src="https://images.theconversation.com/files/172555/original/file-20170606-3681-6cbmw1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/172555/original/file-20170606-3681-6cbmw1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=341&fit=crop&dpr=1 600w, https://images.theconversation.com/files/172555/original/file-20170606-3681-6cbmw1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=341&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/172555/original/file-20170606-3681-6cbmw1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=341&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/172555/original/file-20170606-3681-6cbmw1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=429&fit=crop&dpr=1 754w, https://images.theconversation.com/files/172555/original/file-20170606-3681-6cbmw1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=429&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/172555/original/file-20170606-3681-6cbmw1.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">
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<span class="caption">Lake Chad has been disappearing because of repeated droughts and excessive use of its waters for irrigation.</span>
<span class="attribution"><span class="source">Philippe Rekacewicz, Le Monde diplomatique, February 2008</span></span>
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<p>Rural areas are most at risk from climate change because that’s where most of the population, and most of the poverty, is found. However, urban areas are not safe either, as the country’s growing cities struggle to accommodate the arrival of new residents. Sanitation services like sewage, storm water drainage and waste collection are poor, according to <a href="http://documents.worldbank.org/curated/en/850781470056450919/pdf/ICR3583-07222016.pdf">the World Bank</a>. In the event of floods, as happened in <a href="http://www.irinnews.org/news/2010/11/02">2010</a>, <a href="http://www.healthmap.org/site/diseasedaily/article/cholera-outbreak-likely-worsen-lake-chad-basin-92311">2011</a> and <a href="https://www.theguardian.com/global-development/2012/sep/11/floods-hit-thousands-chad-rains">2012</a>, the infrastructure cannot cope and untreated sewage could infect the water supply, creating a high risk of infectious diseases such as cholera.</p>
<h2>Demographic challenges</h2>
<p>Chad’s population is mostly young, and high youth unemployment has already <a href="http://www.africanews.com/2016/02/05/chad-unemployed-youth-demand-jobs-amid-protests/">caused unrest</a> in the capital N'djamena. Vulnerability to climate is <a href="http://news.trust.org//item/20151117200208-lu75m/">made worse</a> by civil unrest or conflict because people cannot receive the help they need during climate-related disasters such as droughts or floods.</p>
<p>Chad also hosts some <a href="http://www.unhcr.org/en-us/protection/operations/524d81849/chad-fact-sheet.html">300,000 refugees from Darfur</a> on its eastern border with Sudan, according to UN figures, while an additional 67,000 refugees from the Central African Republic are in camps on its southern border. These refugees consume Chad’s limited resources and sometimes compete with the local population. This creates <a href="https://books.google.se/books?id=rlZuAgAAQBAJ&lpg=PP152&dq=%22Among%20those%20who%20survived%20the%20conflict%20are%20many%20whose%20suffering%20continues%22&pg=PP152#v=onepage&q&f=false">resentment and sometimes violence</a> between the refugees and their hosts.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/172693/original/file-20170607-16093-uvzq8l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/172693/original/file-20170607-16093-uvzq8l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/172693/original/file-20170607-16093-uvzq8l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/172693/original/file-20170607-16093-uvzq8l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/172693/original/file-20170607-16093-uvzq8l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/172693/original/file-20170607-16093-uvzq8l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/172693/original/file-20170607-16093-uvzq8l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/172693/original/file-20170607-16093-uvzq8l.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"></a>
<figcaption>
<span class="caption">Farchana refugee camp in eastern Chad.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/eu_echo/8022580592/">European Commission DG ECHO</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>To make matters worse, the Boko Haram crisis in northeastern Nigeria has spilled over to the Lac region of Chad, which now has <a href="http://www.un.org/apps/news/story.asp?NewsID=54575">more than 60,000 displaced people</a> registered there and several thousand more that are unregistered. This is worrying as the country’s unemployed youth, restless and with plenty of time on their hands, could be at risk of recruitment and radicalisation by Boko Haram.</p>
<h2>The way forward</h2>
<p>Despite these challenges, there are ways to mitigate the effect of climate change. For instance, farmers in Chad’s semi-arid Sahelian zone have been using an indigenous rainwater harvesting technique called Zaï to <a href="http://www.academicjournals.org/journal/JAERD/article-full-text/C201D1050066">successfully grow crops</a>. Zaï involves the digging of small pits and sowing crops in them. The pits retain water for a long period of time and are particularly efficient when there isn’t much rain. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/172298/original/file-20170605-16909-1kwl6q4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/172298/original/file-20170605-16909-1kwl6q4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/172298/original/file-20170605-16909-1kwl6q4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/172298/original/file-20170605-16909-1kwl6q4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/172298/original/file-20170605-16909-1kwl6q4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/172298/original/file-20170605-16909-1kwl6q4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/172298/original/file-20170605-16909-1kwl6q4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/172298/original/file-20170605-16909-1kwl6q4.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">Zaï in action (photo taken in neighbouring Niger).</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/cgiarclimate/8057688673/">CGIAR Climate / flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>The Zaï technique was enhanced by introducing manure and compost into the pits to provide nutrients to the crops. This helped rehabilitate soils that are heavily degraded and significantly <a href="http://www.ifpri.org/cdmref/p15738coll2/id/59638/filename/59639.pdf">increased the yields of food crops</a>.</p>
<p>Agroforestry, the combining of crops and trees in the same patch of land, can also help <a href="http://www.sciencedirect.com/science/article/pii/S1877343513001255">mitigate and adapt to the impacts of climate change</a>. Tree roots stabilise soils and protect them from eroding during heavy rainfall, while also restoring fertility simply by producing litter which eventually makes its way back into the earth.</p>
<p>Of course, any country would be better placed to deal with climate change if it simply became much wealthier. Chad began producing petroleum in 2003, and it now accounts for <a href="http://atlas.media.mit.edu/en/profile/country/tcd/">93% of all exports</a>. However, this left the country vulnerable to declines in oil prices. So, when the price did indeed crash in late 2014, Chad suffered a significant loss of revenue. Needless to say, the impact of climate-related disasters such as droughts or floods becomes magnified if the country does not have the resources to combat them.</p>
<p>Chad cannot rely on oil forever. Farming is still the mainstay of its economy and, in the longer term, developing sustainable <a href="http://www.worldbank.org/en/news/press-release/2012/05/17/in-response-to-food-insecurity-in-chad-the-world-bank-boosts-agricultural-investment-to-improve-production">agriculture</a> and <a href="http://www.fao.org/fileadmin/user_upload/drought/docs/Participatory%20range%20land%20management%20RM%20Guideline%20(4).pdf">livestock farming</a> will be key in providing employment and maintaining food security.</p><img src="https://counter.theconversation.com/content/78423/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Abdulhakim Abdi 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>Poverty and conflict mean the nation is struggling to deal with rising temperatures.Abdulhakim Abdi, Sustainability Scientist, Lund UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/746662017-03-16T07:32:34Z2017-03-16T07:32:34ZHumans may have transformed the Sahara from lush paradise to barren desert<figure><img src="https://images.theconversation.com/files/160991/original/image-20170315-5347-75m0uk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"></span> <span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Once upon a time, the Sahara was green. There were vast lakes. Hippos and giraffe lived there, and <a href="http://www.sciencedirect.com/science/article/pii/S0277379114002728">large human populations</a> of fishers foraged for food alongside the lakeshores. </p>
<p>The “<a href="http://www.nature.com/scitable/knowledge/library/green-sahara-african-humid-periods-paced-by-82884405">African Humid Period</a>” or “Green Sahara” was a time between 11,000 and 4,000 years ago when significantly more rain fell across the northern two-thirds of Africa than it does today. </p>
<p>The <a href="http://www.clim-past.net/10/681/2014/cp-10-681-2014.pdf">vegetation</a> of the Sahara was highly diverse and included species commonly found on the margins of today’s rainforests along with desert-adapted plants. It was a highly productive and predictable ecosystem in which hunter-gatherers appear to have flourished.</p>
<p>These conditions stand in marked contrast to the current climate of northern Africa. Today, the Sahara is the <a href="http://help.nationalgeographic.com/customer/portal/articles/1450076-what-is-the-world-s-largest-desert-">largest hot desert in the world</a>. It lies in the subtropical latitudes dominated by high-pressure ridges, where the atmospheric pressure at the Earth’s surface is greater than the surrounding environment. These ridges inhibit the flow of moist air inland.</p>
<h2>How the Sahara became a desert</h2>
<p>The stark difference between 10,000 years ago and now largely exists due to changing <a href="https://earthobservatory.nasa.gov/IOTD/view.php?id=541">orbital conditions of the earth</a> – the wobble of the earth on its axis and within its orbit relative to the sun. </p>
<p>But this period ended erratically. In some areas of northern Africa, the transition from wet to dry conditions occurred <a href="http://www.clim-past.net/6/281/2010/">slowly</a>; in others it seems to have happened <a href="http://www.sciencedirect.com/science/article/pii/S0277379199000815">abruptly</a>. This pattern does not conform to expectations of changing orbital conditions, since such changes are slow and linear.</p>
<p>The most <a href="http://onlinelibrary.wiley.com/doi/10.1029/96GB02690/abstract">commonly accepted theory</a> about this shift holds that devegetation of the landscape meant that more light reflected off the ground surface (a process known as <a href="http://curry.eas.gatech.edu/Courses/6140/ency/Chapter9/Ency_Atmos/Reflectance_Albedo_Surface.pdf">albedo</a>), helping to create the high-pressure ridge that dominates today’s Sahara. </p>
<p>But what caused the initial devegetation? That’s uncertain, in part because the area involved with studying the effects is so vast. But my <a href="http://journal.frontiersin.org/article/10.3389/feart.2017.00004/full">recent paper</a> presents evidence that areas where the Sahara dried out quickly happen to be the same areas where domesticated animals first appeared. At this time, where there is evidence to show it, we can see that the vegetation changes from grasslands into scrublands. </p>
<p><a href="https://global.britannica.com/science/scrubland">Scrub vegetation</a> dominates the modern Saharan and Mediterranean ecosystems today and has significantly more albedo effects than <a href="https://global.britannica.com/science/grassland">grasslands</a>. </p>
<p>If my hypothesis is correct, the initial agents of change were humans, who initiated a process that cascaded across the landscape until the region crossed an ecological threshold. This worked in tandem with orbital changes, which pushed ecosystems to the brink.</p>
<h2>Historical precedent</h2>
<p>There’s a problem with testing my hypothesis: datasets are scarce. Combined ecological and archaeological research across northern Africa is rarely undertaken.</p>
<p>But well-tested comparisons abound in prehistoric and historic records from across the world. Early Neolithic farmers of <a href="http://www.sciencedirect.com/science/article/pii/S0277379113002710">northern Europe</a>, <a href="http://www.nature.com/nature/journal/v449/n7161/full/nature06135.html">China</a> and <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0042442">southwestern Asia</a> are documented as significantly deforesting their environments. </p>
<p>In the case of <a href="http://www.sciencedirect.com/science/article/pii/S0277379109000365">East Asia</a>, nomadic herders are believed to have intensively grazed the landscape 6,000 years ago to the point of reducing evapo-transpiration – the process which allows clouds to form – from the grasslands, which weakened monsoon rainfall.</p>
<p>Their burning and land-clearance practices were so unprecedented that they triggered significant alterations to the relationship between the land and the atmosphere that were measurable within hundreds of years of their introduction. </p>
<p>Similar dynamics occurred when domesticated animals were introduced to <a href="http://onlinelibrary.wiley.com/doi/10.1002/fee.1311/abstract">New Zealand</a> and <a href="http://scholarsarchive.byu.edu/wnan/vol60/iss2/5/">North America</a> upon initial settlement by Europeans in the 1800s – only in these instances they were documented and quantified by historical ecologists.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/161117/original/image-20170316-10892-16uzrb0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/161117/original/image-20170316-10892-16uzrb0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=441&fit=crop&dpr=1 600w, https://images.theconversation.com/files/161117/original/image-20170316-10892-16uzrb0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=441&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/161117/original/image-20170316-10892-16uzrb0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=441&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/161117/original/image-20170316-10892-16uzrb0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=554&fit=crop&dpr=1 754w, https://images.theconversation.com/files/161117/original/image-20170316-10892-16uzrb0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=554&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/161117/original/image-20170316-10892-16uzrb0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=554&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">New Zealand’s colonial pastoralists transformed the country’s landscape.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/History_of_New_Zealand#/media/File:William_Allsworth_-_The_emigrants_-_Google_Art_Project.jpg">William Allsworth</a></span>
</figcaption>
</figure>
<h2>Ecology of fear</h2>
<p>Landscape burning has been occurring for millions of years. Old World landscapes have hosted humans for more than a million years and wild grazing animals for more than 20 million years. Orbitally induced changes in the climate are as old as the earth’s climate systems themselves. </p>
<p>So what made the difference in the Sahara? A theory called the “<a href="https://islandpress.org/book/trophic-cascades">ecology of fear</a>” may contribute something to this discussion. Ecologists recognise that the behaviour of predatory animals toward their prey has a significant impact on landscape processes. For example, deer will avoid spending significant time in open landscapes because it makes them easy targets for predators (including humans).</p>
<p>If you remove the threat of predation, the prey behave differently. In Yellowstone National Park, the absence of predators is argued to have changed grazers’ habits. Prey felt more comfortable grazing alongside the exposed riverbanks, which increased the erosion in those areas. The re-introduction of wolves into the ecosystem completely shifted this dynamic and <a href="https://www.theguardian.com/science/grrlscientist/2014/mar/03/how-wolves-change-rivers">forests regenerated within several years</a>. By altering the “fear-based ecology”, significant changes in landscape processes are known to follow.</p>
<p>The introduction of livestock to the Sahara may have had a similar effect. Landscape burning has a deep history in the <a href="https://www.cambridge.org/core/journals/quaternary-research/article/div-classtitlelate-quaternary-climate-and-vegetation-of-the-sudanian-zone-of-northeast-nigeriadiv/C5E046492209D7C98A4622BBACF7A336">few places in which it has been tested in the Sahara</a>. But the primary difference between pre-Neolithic and post-Neolithic burning is that the ecology of fear was altered. </p>
<p>Most grazing animals will <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4528463/">avoid landscapes that have been burned</a>, not only because the food resources there are relatively low, but also because of exposure to predators. Scorched landscapes present high risks and low rewards. </p>
<p>But with humans guiding them, domesticated animals are not subject to the same dynamics between predator and prey. They can be led into recently burned areas where the grasses will be preferentially selected to eat and the shrubs will be left alone. Over the succeeding period of landscape regeneration, the less palatable scrubland will grow faster than succulent grasslands – and, thus, the landscape has crossed a threshold. </p>
<p><a href="http://journal.frontiersin.org/article/10.3389/feart.2017.00004/full">It can be argued</a> that early Saharan pastoralists changed the ecology of fear in the area, which in turn enhanced scrubland at the expense of grasslands in some places, which in turn enhanced albedo and dust production and accelerated the termination of the African Humid Period. </p>
<p>I tested this hypothesis by correlating the occurrences and effects of early livestock introduction across the region, but more detailed paleoecological research is needed. If proven, the theory would explain the patchy nature of the transition from wet to dry conditions across northern Africa.</p>
<h2>Lessons for today</h2>
<p>Although more work remains, the potential of humans to profoundly alter ecosystems should send a powerful message to modern societies.</p>
<p>More than <a href="http://www.un.org/en/events/desertification_decade/whynow.shtml">35% of the world’s population lives in dryland ecosystems</a>, and these landscapes must be carefully managed if they are to sustain human life. The end of the African Humid Period is a lesson for modern societies living on drylands: if you strip the vegetation, you alter the land-atmosphere dynamics, and rainfall is likely to diminish. </p>
<p>This is precisely what the historic records of rainfall and vegetation in the <a href="https://landcover.usgs.gov/luhna/chap9.php">south-western desert of the United States demonstrates</a>, though the precise causes remain speculative. </p>
<p>In the meantime, we must balance economic development against environmental stewardship. Historical ecology teaches us that when an ecological threshold is crossed, we cannot go back. There are no second chances, so the long-term viability of 35% of humanity rests on maintaining the landscapes where they live. Otherwise we may be creating more Sahara Deserts, all around the world.</p><img src="https://counter.theconversation.com/content/74666/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David K Wright receives funding from the National Research Foundation of Korea, National Geographic Society, the Australian Research Council and the National Science Foundation (USA). </span></em></p>The world’s biggest desert used to be green, lush and full of hippos. A new theory suggests humans could have tipped the environment over the edge.David K. Wright, Associate Professor, Department of Archaeology and Art History, Seoul National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/594172016-05-16T16:08:44Z2016-05-16T16:08:44ZChina’s desertification is causing trouble across Asia<p>Creeping desertification in China is swallowing thousands of square kilometres of productive soil every year. It’s a challenge of gigantic and unprecedented proportions. </p>
<p>The rate of desertification <a href="https://books.google.co.uk/books?id=MceNAgAAQBAJ&pg=PA1&lpg=PA1&dq=almost+40+percent+soil+erosion+desertification+china&source=bl&ots=zTzVzsO9_I&sig=xEz7y0vAMRjc0443zmjwIFSzFgw&hl=en&sa=X&ved=0ahUKEwjiyder-cDMAhXjDMAKHceOD2MQ6AEIiQEwFA#v=onepage&q=almost%2040%20pe">increased</a> throughout the second half of last century and, although this trend has since stabilised, the situation remains <a href="http://www.unccd.int/Lists/SiteDocumentLibrary/Publications/Desertification-EN.pdf">very serious</a>.</p>
<p>More than a quarter of the entire country is now degraded or turning to desert, thanks to “overgrazing by livestock, over cultivation, excessive water use, or <a href="https://books.google.co.uk/books?id=HxU45pURyicC&pg=PA66&dq=desertification+in+china+pace&hl=en&sa=X&ved=0ahUKEwiY0Jn9rtfMAhUDQBoKHf4rDrMQ6AEIQTAH#v=onepage&q=More%20than%20one-quarter%20of%20China's%20land%20is%20now%20affected%20by%20desertification%20or%20is%20degraded%20due%20to%20overgrazing%20by%20livestock%2C%20over%20cultivation%2C%20excessive%20water%20use%2C%20or%20changes%20in%20climate&f=false">changes in climate</a>”. The Gobi desert alone <a href="http://www.aljazeera.com/indepth/features/2012/12/2012126123056457256.html">gobbles up</a> 3,600km<sup>2</sup> of grassland each year. China’s own <a href="http://www.globalpost.com/dispatch/news/science/131211/waterless-world-inner-mongolia-desert-wasteland">State Forestry Administration</a> has identified land desertification as the country’s most important ecological problem, and climate change will only make things worse.</p>
<p>Ecological disasters have social effects. Desertification threatens the subsistence of about a third of China’s population, especially those in the country’s west and north, and could pose serious challenges to <a href="http://globalriskinsights.com/2016/02/chinas-growing-deserts-a-major-political-risk/">political and economic stability</a>. It costs China roughly <a href="http://www.sciencedirect.com/science/article/pii/S2095633915300563">RMB 45 billion (US$6.9 billion)</a> per year.</p>
<p><a href="https://books.google.co.uk/books?id=qaBgAQAAQBAJ&pg=PT29&lpg=PT29&dq=%2223.16%22+%22for+seriously+desertified+regions%22&source=bl&ots=BLhpBnc4Xj&sig=cmaa16_BQCLolWMglqzmZTG3y6c&hl=en&sa=X&ved=0ahUKEwjs6fOarNfMAhVHChoKHceOCqYQ6AEIJDAB#v=onepage&q=%2223.16%22%20%22for%20seriously%20desertified%20regions%22&f=false">Research</a> shows that “for seriously desertified regions, the loss amounts to as much as 23.16% of … annual GDP”. The fact that one third of the country’s land area is eroded has led some 400m people to struggle to cope with a lack of productive soil, destabilised climatological conditions and severe water shortages. <a href="http://www.albany.edu/%7Eyhuang/LiuAndDiamond_chinasenvironmentinaglobalizingworld.pdf">Droughts</a> damage “about 160,000 square kilometres of cropland each year, double the area damaged in the 1950s”. </p>
<p>Blaming the desertification on overgrazing and bad cultivation, the state has since 2005 started to reallocate millions of people from dry and barren territories under its <a href="https://books.google.co.uk/books?id=IRB_AAAAQBAJ&pg=PT354&lpg=PT354&dq=%22ecological+migration%22+million&source=bl&ots=CP0cDcQ1h5&sig=XSAKCenMAgJ1MPI7K13f1B62V_I&hl=en&sa=X&ved=0ahUKEwiegIG9-MXMAhXGL8AKHXJ2CosQ6AEINTAF#v=onepage&q=%22ecological%20migration%22%20million&f=false">controversial</a> and <a href="http://www.rfa.org/english/news/china/four-herders-jailed-02032015112302.html">hotly-contested</a> “ecological migration” programme.</p>
<p>Deforestation has only made things worse. <a href="http://www.greenpeace.org/eastasia/campaigns/forests/problems/china-remaining-forests/">Greenpeace</a> writes that only 3.34% of the country’s original forests remain intact, of which “only 0.1% is fully protected”. </p>
<p>Despite extraordinary efforts by the government to reduce the rate of erosion, culminating in the <a href="http://www.economist.com/news/international/21613334-vast-tree-planting-arid-regions-failing-halt-deserts-march-great-green-wall">largest reforestation project</a> ever undertaken, the government itself <a href="http://www.theguardian.com/world/2011/jan/04/china-desertification">conceded</a> in 2011 that the “desertification trend has not fundamentally reversed”.</p>
<h2>Stormy geopolitics</h2>
<p>Dust and sand storms have intensified and now pose provocative geopolitical challenges. The Gobi desert which spans China and Mongolia is the world’s <a href="http://www.sciencedirect.com/science/article/pii/S1875963711000085">second largest dust source</a>, after the Sahara. Whirling soil sediments are an annual plague in western China but also move all the way across the Pacific and beyond. Traces of China’s deserts have been found as far away as <a href="http://link.springer.com/book/10.1007%2F978-3-540-88254-1">New Zealand</a> or the <a href="http://onlinelibrary.wiley.com/doi/10.1029/2002GL016833/full">French Alps</a>, and “yellow dust” costs the <a href="http://www.kossrec.org/wp-content/uploads/2015/04/Socio-Economic_Costs_from.pdf">Korean</a> and <a href="http://www.taipeitimes.com/News/world/archives/2004/04/01/2003116225">Japanese</a> economies billions of US dollars each year. Even worse off is Mongolia, which itself is facing desertification, and will be particularly affected by <a href="http://www.theglobeandmail.com/news/world/the-globe-in-mongolia-why-a-herding-culture-is-dyingout/article29791679/">global warming</a>.</p>
<p>Inhaling this dust has devastating effects on the health of animals and humans alike. Asian dust has in the past decade been <a href="http://www.ncbi.nlm.nih.gov/pubmed/12359184">linked</a> to both cardiovascular and respiratory diseases while more recent <a href="http://www.sciencedirect.com/science/article/pii/S1352231013005049">research</a> discovered “a statistically significant association between Asian dust storms and daily mortality”. </p>
<p>Dust storms also transport toxic pollutants, bacteria, viruses, pollen and fungi. <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1932751/">Microbiologists</a> looked at a dust storm in South Korea and found big increases in aerial bacteria.</p>
<h2>Working together to fight the dust</h2>
<p>Dust and sand storms don’t respect international borders, so it’s no wonder they have become a big worry for multilateral governance. Back in 2005 the Asian Development Bank, together with several UN agencies and regional countries, drew up a <a href="http://www.adb.org/publications/prevention-and-control-dust-and-sandstorms-northeast-asia">master plan</a> to promote <a href="http://www.preventionweb.net/files/1821_1821VL102237.pdf">cooperative solutions</a>.</p>
<p>More recently, dust was <a href="http://english.yonhapnews.co.kr/national/2015/11/01/0301000000AEN20151101003900315.html">on the agenda</a> at a 2015 trilateral summit attended by South Korea, Japan and China. Environment ministers from the three countries <a href="http://www.env.go.jp/earth/coop/coop/english/dialogue/temm.html">meet each year</a> and have established <a href="http://eng.me.go.kr/eng/web/board/read.do?menuId=21&boardMasterId=522&boardId=508100">special working groups</a> to “improve forecasting accuracy and to develop measures of vegetation restoration in source areas in China”.</p>
<p>These are positive steps. China can’t pretend its desertification is its own problem as the effects on other countries are too obvious. Swirling dust storms have forced other states to take a direct interest in China’s desert sands.</p>
<hr>
<p><em>A version of this article also appears on the University of Nottingham’s <a href="http://blogs.nottingham.ac.uk/chinapolicyinstitute/2016/05/09/the-geopolitics-of-desertification-in-china-2/">China Policy Institute Blog</a>.</em></p><img src="https://counter.theconversation.com/content/59417/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marijn Nieuwenhuis 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>As grassland turns to desert, dust is blown into the atmosphere and across oceans.Marijn Nieuwenhuis, Teaching Fellow in International Relations and East Asia, University of WarwickLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/469422015-09-02T04:40:31Z2015-09-02T04:40:31ZThe impact of savanna fires on Africa’s rainfall patterns<figure><img src="https://images.theconversation.com/files/93550/original/image-20150901-13401-zpl9uk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fires, such as this one in eastern Sierra Leone, are an annual occurrence across Africa.</span> <span class="attribution"><span class="source">Reuters/Finbarr O'Reilly</span></span></figcaption></figure><p>Beginning in late October the steady summer rains of the north African savanna abate, and subsistence farmers begin the millennia-old tradition of burning the savanna and open woodland for pastoral land clearing and shifting cultivation. </p>
<p>These fires are very <a href="http://onlinelibrary.wiley.com/doi/10.1029/96JD01835/full">common</a>. Africa’s savanna fires comprise the largest proportion (71%) of areas burned <a href="http://onlinelibrary.wiley.com/doi/10.1002/jgrg.20042/abstract">globally</a> and the trees, shrubs and grasses are well adapted to fire.</p>
<p>However, prior to human settlement, the majority of fires occurred during the summer wet season, when natural ignitions from lightning dominated the fire regime. But with the progression of civilisation from nomadic times to one where agriculture is so important, the <a href="http://www.pnas.org/content/109/3/847.short">fire regime</a> and use of fire for crops has changed drastically. Now, most fires occur during the dry season as a direct consequence of agropastoral ignitions.</p>
<p>These fires, which burn continuously from late November through early March, emit massive amounts of microscopic particulates, otherwise known as smoke. Some estimates <a href="http://www.falw.vu/%7Egwerf/GFED/GFED4/tables/">suggest</a> that emissions of elemental carbon exceed 400 million tonnes annually, 6.7 million of which are emitted as microscopic particulates. Of particular importance are the 375,000 tonnes that are emitted as dark particulates known as black carbon, which efficiently absorbs sunlight and interacts with clouds and climate in numerous ways.</p>
<p>Research shows that smoke has climatic implications which are not innocuous. A recent <a href="http://news.sciencemag.org/asiapacific/2015/07/catastrophic-chinese-floods-triggered-air-pollution">study</a> of a region in China is one such example. It concludes that suppression of rainfall near the source of industrial smoke emissions caused the non-precipitated moisture to relocate to a nearby mountainous area. This led to dangerous, flooding rains on the mountain slopes. Globally previous <a href="http://www.atmos-chem-phys.net/13/5227/2013/acp-13-5227-2013.html">research</a> shows that emissions of smoke from fires can disrupt the large-scale <a href="http://www.seas.harvard.edu/climate/eli/research/equable/hadley.html">Hadley Circulation</a> that delivers rain to the tropics and dry weather to the deserts.</p>
<p>In research <a href="http://onlinelibrary.wiley.com/doi/10.1002/2015GL065063/abstract">recently published,</a> we explore this question in more detail. We used satellite measurements from the <a href="https://www-misr.jpl.nasa.gov/">Multi-angle Imaging Spectroradiometer</a> and the <a href="http://modis.gsfc.nasa.gov/">Moderate Resolution Imaging Spectrometer</a> to determine whether human modification of Africa’s fire regime has unforeseen effects on regional climate. </p>
<p>We found that four-day periods of very low cloud cover coincided with spikes in both fire ignitions and fire emissions. This suggests the existence of a positive feedback loop, whereby fires limit rainfall and reduce cloud cover. This dries and warms the surface and makes it easier for farmers to burn and fires to spread. Over time, the increased burning could extend the dry season.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/93555/original/image-20150901-13435-ia9hbd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/93555/original/image-20150901-13435-ia9hbd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=384&fit=crop&dpr=1 600w, https://images.theconversation.com/files/93555/original/image-20150901-13435-ia9hbd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=384&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/93555/original/image-20150901-13435-ia9hbd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=384&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/93555/original/image-20150901-13435-ia9hbd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=482&fit=crop&dpr=1 754w, https://images.theconversation.com/files/93555/original/image-20150901-13435-ia9hbd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=482&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/93555/original/image-20150901-13435-ia9hbd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=482&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A fire rages in Upper Nile State.</span>
<span class="attribution"><span class="source">Reuters/Goran Tomasevic</span></span>
</figcaption>
</figure>
<h2>How smoke influences rainfall</h2>
<p>The relationship between smoke and rainfall is complicated. The formation of clouds requires microscopic particulates that provide a solid surface on which atmospheric water vapour can condense. Based on this, it seems that smoke should facilitate cloud formation and rainfall. But the development of rain clouds in this region occurs primarily via convection, which is a meteorological process determined by the vertical mixing of air.</p>
<p>Smoke from fires contains a high percentage of black carbon particulates, one type of aerosol. These aerosols efficiently absorb sunlight much like the Earth’s surface does on a hot afternoon. As the suspended aerosols absorb sunlight, they heat the air and create a warm layer that prevents air from the Earth’s warmed surface from rising above it.</p>
<p>Our research shows that, as a result of the black carbon heating, the upward motion of air necessary to fuel convection diminished and produced a notable suppression of rainfall in the region. Across all of the thousands of data points analysed, daytime convection was less in smoky scenes than in non-polluted scenes. This was even after extensively accounting for meteorological conditions.</p>
<h2>The unknowns</h2>
<p>The fire-driven reduction in rainfall has immediate implications for the fire regime. Besides the obvious impacts on surface temperature (it would get warmer), precipitation (it would get drier) and climate (it would change the global distribution of rainfall), the reduction in rainfall could also influence the local ignition and spread of fire.</p>
<p>What are the implications of this continent-scale positive feedback loop on global climate warming, and is there any way to preserve the millennia-old burning practices of farmers while still considering the massive effect on climate? These are unanswered questions that we still hope to explore.</p><img src="https://counter.theconversation.com/content/46942/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Tosca receives funding from the National Aeronautics and Space Administration.</span></em></p>On the African continent, more fire for crops leads to less rainfall.Michael Tosca, Research Scientist, Jet Propulsion Laboratory & University of California, Los Angeles, NASALicensed as Creative Commons – attribution, no derivatives.