tag:theconversation.com,2011:/au/topics/lca-2324/articlesLCA – The Conversation2021-09-15T12:15:31Ztag:theconversation.com,2011:article/1655132021-09-15T12:15:31Z2021-09-15T12:15:31ZMenstrual cups are a cheaper, more sustainable way for women to cope with periods than tampons or pads<figure><img src="https://images.theconversation.com/files/419889/original/file-20210907-19-1h6r7e9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A woman holds a menstrual cup in Kenya. </span> <span class="attribution"><a class="source" href="https://theconversation.com/asset_images/419889/edit?content_id=165513">Gioia Forster/picture alliance via Getty Images</a></span></figcaption></figure><p><em>Every year in America, women spend at least <a href="https://www.statista.com/statistics/192658/us-tampon-sales-via-different-sales-channels-in-2010-and-2011/">US$2.8 billion on sanitary pads and tampons</a> that can take <a href="https://www.nationalgeographic.com/environment/article/how-tampons-pads-became-unsustainable-story-of-plastic">hundreds of years to decompose</a>. Is there a more economical and environmentally friendly way? To find out, we asked <a href="https://www.clarkson.edu/people/susan-powers">Susan Powers</a>, a professor of sustainable environmental systems at Clarkson University about her work comparing the environmental impact of tampons, sanitary pads and menstrual cups.</em></p>
<p><strong>What is a menstrual cup?</strong></p>
<p>A <a href="https://www.healthline.com/health/womens-health/menstrual-cup">menstrual cup</a> is a type of reusable feminine hygiene product. It’s a small, flexible bell-shaped cup made of rubber or silicone that a woman inserts into her vagina to catch and collect menstrual fluid. It can be used for up to 12 hours, after which it is removed to dispose of the fluid and cleaned. The cup is rinsed with hot water and soap between each insertion and sterilized in boiling water at least once per period. A cup can last <a href="https://doi.org/10.1016/S2468-2667(19)30111-2">up to 10 years</a>. </p>
<p>Although menstrual cups have been around for decades, they historically have been <a href="https://www.theguardian.com/us-news/2020/aug/31/menstrual-cups-tampons-period-money">less popular</a> than pads or tampons. </p>
<p><strong>Are menstrual cups growing in popularity?</strong></p>
<p><a href="https://www.globenewswire.com/news-release/2020/03/26/2006946/0/en/Menstrual-Cups-Industry-Analysis-2019-2020-2027-Shift-Towards-Reusable-Menstrual-Products-Favours-Growth.html">Yes</a>, their popularity is growing as women, as well as men, become more comfortable dealing with and discussing menstruation. They have been a topic in news media ranging from <a href="https://www.teenvogue.com/story/menstrual-cups-everything-you-need-to-know">Teen Vogue</a> to <a href="https://www.npr.org/sections/goatsandsoda/2019/07/17/742370168/menstrual-cups-they-re-safe-to-use-and-people-like-using-them">NPR</a>. Another part of their growing popularity stems from the <a href="https://www.forbes.com/sites/meghnasarkar/2019/01/20/plastic-free-periods-why-women-need-to-go-green-during-that-time-of-the-month/?sh=5629bf7a1701">general public’s concern about solid waste</a> associated with any disposable product, including disposable pads and tampons.</p>
<p><strong>You have been researching the life cycle of different feminine hygiene products. What is a life cycle assessment and what have your studies shown?</strong></p>
<p>A <a href="https://ecochain.com/knowledge/life-cycle-assessment-lca-guide/">life cycle assessment</a> provides a broad accounting and evaluation of all of the materials, energy and processes associated with the raw materials in a product, including their extraction, manufacture, use and disposal. Impacts considered include climate change, natural resource depletion, human toxicity and ecotoxicity, among others. </p>
<p>I have worked for several years on a <a href="https://www.clarkson.edu/people/susan-powers">range of these assessments</a> for consumer products and energy and agricultural systems. When Clarkson Honors Program student Amy Hait approached me about her idea of completing a life cycle assessment on feminine hygiene products, I was intrigued and happy to work closely with her to complete the study and <a href="https://doi.org/10.1016/j.resconrec.2019.104422">publish the results in the journal Resources, Conservation & Recycling</a>. </p>
<p>We compared three products: a <a href="https://www.ubykotex.com/en-us/products/tampons/compact/click-regular">rayon-based tampon</a> with a plastic applicator, a <a href="https://www.ubykotex.com/en-us/products/pads/maxi/security-regular">maxipad with a cellulose and polyethylene absorbent core</a> and a <a href="https://divacup.com/our-products-collections/">menstrual cup made of silicone</a>. </p>
<p>The assessment also included packaging materials and the processes to make and transport these materials. In order to make a fair comparison among products, we looked at the number of products used by an average woman in one year. Based on <a href="https://www.huffpost.com/entry/period-cost-lifetime_n_7258780?guccounter=1">published average values</a>, that would be 240 tampons or maxipads. A menstrual cup has a 10-year lifespan, so its use for one year is the equivalent of one-tenth of the overall manufacturing and disposal impact.</p>
<p>Our assessment included eight different categories to evaluate the overall environmental impact. These include measuring the impacts on the environment and human health. </p>
<p>The life cycle impact assessment provides quantitative scores for the impacts of each of these individually. We also used normalization factors for the United States to enable us to come up with a total impact score. Higher scores reflect greater overall impacts.</p>
<p><strong>Is using a menstrual cup more environmentally sustainable?</strong></p>
<p>The results of the life cycle assessment clearly showed that the reusable menstrual cup was by far the best based on all environmental metrics. Based on the total impact score, the maxipad we considered in our study had the highest score, indicating higher impacts. The tampon had a 40% lower score and the menstrual cup 99.6% lower. The key factor for the high score for the maxipad was its greater weight and the manufacture of the raw materials to make it. </p>
<p>Most people choose a reusable product because they believe it won’t add waste to landfills. But our study shows that most environmental benefits are from the reduced need to prepare all of the raw materials and manufacture the product. </p>
<p>Taking the tampon as an example, the extraction and preparation of the raw materials used to make it contributed over 80% of the total impact. Disposal, which people often pay more attention to, really contributes substantially only to water pollution, which is a very minor component of the overall impact. </p>
<p>The life cycle assessment also identifies sometimes surprising sources of environmental and health impacts, including dioxins from bleaching wood pulp for pads, zinc from rayon production for tampons and chromium emissions from fossil fuel energy sources. By not having to produce more single-use products, we can avoid emitting many of these pollutants. </p>
<p>[<em>Get the best of The Conversation, every weekend.</em> <a href="https://theconversation.com/us/newsletters/weekly-highlights-61?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=weeklybest">Sign up for our weekly newsletter</a>.]</p>
<p>As with any other consumer goods, the impacts associated with the manufacture and disposal of products are greatly reduced the more times you reuse anything. Using a reuseable cup for even just one month instead of the average 20 pads or tampons was still an environmentally preferable approach. </p>
<p><strong>What is done to encourage the use of a more sustainable feminine hygiene product?</strong></p>
<p>The taboo nature of talking about menstruation is changing with young women, at least in the United States. <a href="https://www.facebook.com/cusustainability/posts/3699047843465349">Women at Clarkson University, for example</a>, worked with a cup manufacturer to provide a very public giveaway program to distribute free cups to over 100 college students. That would never have happened when I was a student decades ago. Many health-related web sites like <a href="https://www.webmd.com/women/guide/menstrual-cup">WebMD</a> and <a href="https://www.healthline.com/health/womens-health/menstrual-cup">Healthline</a> provide relevant and reliable information on the proper use and care of menstrual cups, which should help to reduce concerns over their use and encourage more women to try them.</p><img src="https://counter.theconversation.com/content/165513/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Susan Powers does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Menstruation cups are increasingly being used as an environmentally friendly alternative to tampons and sanitary pads.Susan Powers, Spence Professor of Sustainable Environmental Systems and the Director of the Institute for a Sustainable Environment, Clarkson UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/102132012-10-30T19:04:20Z2012-10-30T19:04:20ZPink batts: not a scandal, but not as good as claimed<figure><img src="https://images.theconversation.com/files/16719/original/5rmqqw6g-1350615342.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Insulation can dramatically reduce emissions, but there are emissions costs as well.</span> <span class="attribution"><span class="source">Wei-Hang Chua</span></span></figcaption></figure><p>The words “pink batts scheme” are rarely heard without “debacle”. But a recent Insulation Council of Australia <a href="http://www.icanz.org.au/pdf/2011_ICANZ_Report2_-_V10d_.pdf">report</a> by Energy Efficient Strategies (EES) has described the government’s home insulation program as an environmental success. Unfortunately, the report doesn’t take account of all emissions associated with insulation.</p>
<p>The nationwide insulation scheme was abandoned quickly following the death of four workers, house fires, and many maintenance interventions. But the Insulation Council of Australia suggests that finishing the job and insulating the remaining houses across Australia would yield significant monetary savings. It would also reduce energy consumption and greenhouse gas emissions. </p>
<p>By 2020, the report claims that insulating Australia’s houses would save at least 38 petajoules of energy (equivalent to lighting all Australian households for one and a half years) and avoid 14 Mt of CO<sub>2</sub>-e greenhouse gas emissions. </p>
<p>However, these estimated energy and greenhouse gas emissions savings do not take into account the full environmental implications associated with installing insulation.</p>
<p>Most energy efficiency studies focus solely on the operational aspect of buildings, such as the energy it takes to heat and cool them. However, various studies have proven that the energy and emissions required to manufacture building products, such as insulation, can be just as significant. When they’re calculated using a comprehensive assessment technique, which includes all of the energy expended across the entire supply chain, the so-called “embodied” energy and emissions of a building can be equivalent to 50 years worth of a building’s operational energy requirement. </p>
<p>The energy and emissions embodied in the manufacture of insulation is completely ignored in the recent report by Energy Efficient Strategies.</p>
<p>To address this omission, we have conducted a life cycle energy and emissions analysis based on the data used by Energy Efficient Strategies. We complemented this with embodied energy and emissions figures for the manufacture of insulation. </p>
<p>As shown in Figure 1, our findings suggest that even by 2020 the net energy savings of all insulation scenarios (excluding duct insulation for lack of data) considered in the original report are still negative. This is because the initial energy required to produce the insulation batts is still greater than the accumulated energy savings for heating and cooling (until up to 2023 for the floor insulation scenario). </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/16676/original/hhqpr4bt-1350533897.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/16676/original/hhqpr4bt-1350533897.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/16676/original/hhqpr4bt-1350533897.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=324&fit=crop&dpr=1 600w, https://images.theconversation.com/files/16676/original/hhqpr4bt-1350533897.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=324&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/16676/original/hhqpr4bt-1350533897.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=324&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/16676/original/hhqpr4bt-1350533897.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=407&fit=crop&dpr=1 754w, https://images.theconversation.com/files/16676/original/hhqpr4bt-1350533897.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=407&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/16676/original/hhqpr4bt-1350533897.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=407&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Figure 1: Energy savings.</span>
</figcaption>
</figure>
<p>Similarly, in 2020 the net greenhouse gas emissions abatement is totally negligible because the insulation is just starting to pay back its embodied emissions (see Figure 2). </p>
<p>However, once all houses are insulated and embodied energy and emissions have been paid back by operational savings, the insulation saves increasing amounts of energy and prevents the emission of millions of tonnes of greenhouse gases into the future (assuming continued optimal performance of the insulation batts). </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/16677/original/29pryzxk-1350533898.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/16677/original/29pryzxk-1350533898.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/16677/original/29pryzxk-1350533898.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=328&fit=crop&dpr=1 600w, https://images.theconversation.com/files/16677/original/29pryzxk-1350533898.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=328&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/16677/original/29pryzxk-1350533898.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=328&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/16677/original/29pryzxk-1350533898.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=413&fit=crop&dpr=1 754w, https://images.theconversation.com/files/16677/original/29pryzxk-1350533898.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=413&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/16677/original/29pryzxk-1350533898.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=413&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Figure 2: Greenhouse gas abatement.</span>
</figcaption>
</figure>
<p>In 2030, the total energy saved is estimated (conservatively) at 314 PJ and the total emissions avoided are 22 Mt of CO<sub>2</sub>-e. </p>
<p>This shows that in the long term, insulation will not only pay back its embodied energy requirements and emissions but will also result in significant energy savings and greenhouse gas emissions reductions while being cost effective.</p>
<p>We agree with the main findings of the Energy Efficient Strategies report, that insulating buildings can result in a significant reduction in energy demand and emissions. But a more holistic view indicates that the possible savings are likely to be less and take considerably longer to achieve. </p>
<p>In addition, it is also important to consider other aspects in the assessment of the benefits of insulating our buildings, such as the release of pollutants, production of waste and depletion of resources associated with manufacturing insulation products.</p><img src="https://counter.theconversation.com/content/10213/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robert Crawford receives funding from the Australian Research Council.</span></em></p><p class="fine-print"><em><span>André Stephan receives funding from the Belgian National Fund for Scientific Research (F.R.S. -FNRS) and Wallonia-Brussels International (WBI).</span></em></p>The words “pink batts scheme” are rarely heard without “debacle”. But a recent Insulation Council of Australia report by Energy Efficient Strategies (EES) has described the government’s home insulation…Robert Crawford, Lecturer in Construction and Environmental Assessment, The University of MelbourneAndré Stephan, Postdoctoral Research Fellow, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/84982012-08-27T20:45:27Z2012-08-27T20:45:27ZSoy versus dairy: what’s the footprint of milk?<figure><img src="https://images.theconversation.com/files/14429/original/56x8k435-1345440935.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Soy might seem simply better, but what do the figures say?</span> <span class="attribution"><span class="source">mc5556/Flickr</span></span></figcaption></figure><p>Are soy milk’s environmental attributes based on substance or froth? Is soy a sustainable solution in the dairy debate?</p>
<p>Comparative environmental analysis of different food groups is like comparing, well, apples and oranges.</p>
<p>Reports such as the Food and Agriculture Organization’s (FAO) <a href="http://www.fao.org/docrep/010/a0701e/a0701e00.HTM">Livestock’s Long Shadow</a> document the negative environmental impacts of cattle and dairy production and consumption. </p>
<p>If cattle are major emitters of the intensive greenhouse gas methane and use large amounts of water, are protein alternatives such as soy less harmful to the environment?</p>
<p>Soy, of course, is much more than soy milk. <a href="http://www.csiro.au/promos/ozadvances/Series6Soy.html">According to the CSIRO</a>, “60 per cent of all products at the supermarket already contain soybean”. (Look at the ingredients lists on breads, flours, oils, pet food and sausages, for example.)</p>
<p>The Federal Department of Agriculture, Fisheries & Forestry’s (DAFF’s) Australian Food Statistics (2011) <a href="http://www.daff.gov.au/__data/assets/pdf_file/0015/2144103/aust-food-statistics-2011-1023july12.pdf">report</a> states that Australia produced 47kt of soybeans in 2010-11 and imported $36M worth of oilseeds in 2010-11 (soybean is classified as an oilseed rather than a pulse). </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/14428/original/dgd4p97v-1345440935.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/14428/original/dgd4p97v-1345440935.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=395&fit=crop&dpr=1 600w, https://images.theconversation.com/files/14428/original/dgd4p97v-1345440935.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=395&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/14428/original/dgd4p97v-1345440935.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=395&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/14428/original/dgd4p97v-1345440935.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=496&fit=crop&dpr=1 754w, https://images.theconversation.com/files/14428/original/dgd4p97v-1345440935.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=496&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/14428/original/dgd4p97v-1345440935.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=496&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In 15 years, world production of soya has doubled.</span>
<span class="attribution"><span class="source">Carol Von Canon</span></span>
</figcaption>
</figure>
<p>According to <a href="http://www.csiro.au/Organisation-Structure/Divisions/Plant-Industry/AndrewJames.aspx">Dr Andrew James</a>, who leads CSIRO’s soybean breeding program, the vast majority of whole-bean soy products Australians consume - such as tofu, soy milk and many baking products - derive from Australian grown beans. However, the soy components used in processed foods generally come from imported soy protein powder, isolate or lecithin.</p>
<p>“We also import 500 to 800,000 tonnes of soybean meal. A crude guess is that would cost about $600 a tonne. That’s $500 million or more,” says Dr James.</p>
<p>Australians have been developing a taste for soy milk over the last decade. A <a href="http://www.australianoilseeds.com/soy_australia">Soy Australia</a> <a href="http://www.australianoilseeds.com/__data/assets/pdf_file/0005/8177/Industry__and__Market_Review_2011.pdf">report</a> showed in 2009 Australians drank three litres each of soy milk a year. This is a 50% increase on 1998.</p>
<p>The report also claimed that most of the soy milk production in Australia is based on imported soy protein or soy protein isolate, a refined form of soy protein made from defatted soy flour. </p>
<p>Says Dr James: “If the milk is made from whole beans it will be Australian-grown beans that are used. If made from protein powder or isolate then that will be imported.”</p>
<p>In 2010-11, Australians <a href="http://www.daff.gov.au/__data/assets/pdf_file/0015/2144103/aust-food-statistics-2011-1023july12.pdf">drank 2296 ML</a> of “dairy milk”, and 2061 ML in 2005-06. The annual average 2005-07 milk consumption per Australian was 230kg (approximately 223 litres).</p>
<p>Soy milk, soy-based drinks, soy dairy-free products and energy bars showed the strongest growth. Traditional foods like tofu have seen a decline in the past couple of years.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/14427/original/njk4m4x9-1345440934.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/14427/original/njk4m4x9-1345440934.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/14427/original/njk4m4x9-1345440934.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/14427/original/njk4m4x9-1345440934.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/14427/original/njk4m4x9-1345440934.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/14427/original/njk4m4x9-1345440934.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/14427/original/njk4m4x9-1345440934.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">It takes less energy to produce soy beans than cows’ milk.</span>
<span class="attribution"><span class="source">Melissa Powers</span></span>
</figcaption>
</figure>
<p>Australian data on the environmental impact of the dairy and soy industries is not as comprehensive as from other countries such as Sweden, Denmark and the United Kingdom. While there are international differences in production, life cycle analysis research is informative.</p>
<p>A <a href="http://www.ajcn.org/content/89/5/1704S.short">recent Swedish study</a> showed a span of 0.4 to 30kg of CO₂ equivalents produced per kilogram for different food items. The lowest emissions per kilogram were from legumes, poultry, and eggs. The highest were from beef, cheese and pork.</p>
<p>Cornell University scientist, David Pimentel, <a href="http://www.organicvalley.coop/fileadmin/pdf/ENERGY_SSR.pdf">has found</a> it takes about 14 kilo-calories (kcal) of fossil-fuel energy to produce 1kcal of milk protein using conventional milk production. Organically produced milk might require a little less than 10kcal of fossil-fuel energy per kcal.</p>
<p>In comparison, Pimentel’s data suggests that in a conventional soybean production system, one kcal of fossil energy invested produces about 3.2kcal of soybean. For 1kcal of fossil energy invested in <em>organic</em> soybean production, you get an average of 3.8kcal of soybeans. This means it takes between .26 and .31kcal of fossil fuel to make 1kcal of soybeans (contrasted with 10-14kcal to make 1kcal of dairy milk protein). </p>
<p>Pimentel states that soy protein accounts for about 35% of those kilocalories, so it appears that making soy protein is more energy-efficient than dairy protein.</p>
<p>Soy milk, of course, is the sum of its parts and whether using ground soy beans or soy isolate, other ingredients are added to make the liquid that consumers use in their coffees and cereals. These extras include calcium and oil. So the production process and its energy and water components need to be considered.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/14430/original/mwf68kdt-1345441411.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/14430/original/mwf68kdt-1345441411.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=463&fit=crop&dpr=1 600w, https://images.theconversation.com/files/14430/original/mwf68kdt-1345441411.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=463&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/14430/original/mwf68kdt-1345441411.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=463&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/14430/original/mwf68kdt-1345441411.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=582&fit=crop&dpr=1 754w, https://images.theconversation.com/files/14430/original/mwf68kdt-1345441411.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=582&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/14430/original/mwf68kdt-1345441411.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=582&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Soy beans have a low and energy footprint, but then there’s the footprint of converting beans to milk.</span>
<span class="attribution"><span class="source">gallixsee media/flickr</span></span>
</figcaption>
</figure>
<p>A 2010 “current and possible futures” <a href="https://dspace.lib.cranfield.ac.uk/bitstream/1826/6497/1/Greenhouse_gas_emissions_from_UK_food-2010.pdf">study</a> into greenhouse gas emissions across the top 45 food commodities in the UK recommended dairy milk and products be replaced by soy-based milk products.</p>
<p>A recent <a href="http://www.sciencedirect.com.ezproxy.lib.uts.edu.au/science/article/pii/S1470160X11004110">Dutch study</a> comparing the water footprints of soybean and equivalent animal products found that soy milk and the soy burger have much smaller water footprints than cow milk and the average beef burger. The water footprint of the soy milk products analysed in this study was 28% of the water footprint of the global average cow milk. The water footprint of the soy burger examined was 7% of the water footprint of the average beef burger in the world.</p>
<p>Another important environmental parameter to consider is how much <a href="https://theconversation.com/time-for-policy-action-on-global-phosphorus-security-5594">phosphorus</a> is used to produce food. Modern agriculture is dependent on phosphorus derived from phosphate rock. It’s a non-renewable resource, and current global reserves <a href="https://theconversation.com/securing-phosphorus-food-for-thought-and-food-for-the-future-756">may be depleted</a> in 50 to 100 years. Meat and livestock production are associated with high phosphorus use and a vegetarian diet <a href="http://www.sciencedirect.com.ezproxy.lib.uts.edu.au/science/article/pii/S095937800800099X">demands significantly less</a> phosphate fertilizer than a meat-based diet.</p>
<p>The genetic modification (GM) debate is a series on its own, but it is relevant to note that all soybeans grown in Australia are GM-free, according to CSIRO’s Dr James. He compares this to the US, Canada, Argentina and Brazil, where over 90% of the soybeans grown are genetically modified.</p>
<p>Dr James says that if the soy milk bought in Australia states it is made from whole soybeans, it is “most likely” made from non-GM Australian soybeans. If the label says it is made from soybean isolate, it is “most probably imported from the US”.</p>
<p>Coffee anyone?</p><img src="https://counter.theconversation.com/content/8498/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Judy Friedlander 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>Are soy milk’s environmental attributes based on substance or froth? Is soy a sustainable solution in the dairy debate? Comparative environmental analysis of different food groups is like comparing, well…Judy Friedlander, Post-graduate Researcher, Institute for Sustainable Futures, University of Technology SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/56232012-03-01T19:34:11Z2012-03-01T19:34:11ZDon’t let figures befuddle you; you can live a low-carbon life<figure><img src="https://images.theconversation.com/files/8197/original/brp5yxft-1330479832.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">We can compare houses and lifestyles.</span> <span class="attribution"><span class="source">Mike Wilson</span></span></figcaption></figure><p>Recent articles on <a href="https://theconversation.com/getting-practical-with-push-for-zero-carbon-homes-5301#comment_22227">low carbon homes</a> and life cycle <a href="https://theconversation.com/you-cant-manage-emissions-until-you-can-measure-them-and-its-harder-than-you-think-4518">measurement difficulties</a> left carbon groupies concerned about the complexity involved in measuring our emissions.</p>
<h2>Measuring emissions isn’t as hard as they make out</h2>
<p>While never just a back of the envelope calculation, measuring emissions is now relatively straight forward. Integrating the <a href="http://www.abs.gov.au/ausstats/abs@.nsf/mf/5209.0.55.001">national input-output tables</a> (financial flows between all that sectors that generate GDP) with national physical and social accounts for water, landuse, greenhouse gases, employment and so on, gives intensity figures for each dollar spent. That is, we can see the kilograms of greenhouse emissions per dollar spent on air travel, restaurant meals, a motor car or a visit to the doctor. </p>
<p>Multiplying the financial breakdown of a building project by these physical intensities gives the full life-cycle emissions of the building and its contents. Repeating this for the spending patterns of the inhabitants quantifies their carbon lifestyle. </p>
<p>A comprehensive report for the Australian economy - <a href="http://www.csiro.au/Outcomes/Environment/Population-Sustainability/BalancingAct.aspx">Balancing Act</a> - was published in 2005 under the guise of triple bottom line accounting. The structural path analysis tool used with this whole-economy accounting reveals all inputs into the production chain and thus allows the search for lower carbon alternatives. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/8199/original/3knfdbns-1330480363.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/8199/original/3knfdbns-1330480363.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/8199/original/3knfdbns-1330480363.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/8199/original/3knfdbns-1330480363.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/8199/original/3knfdbns-1330480363.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/8199/original/3knfdbns-1330480363.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/8199/original/3knfdbns-1330480363.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">We have the numbers to make decisions on housing.</span>
<span class="attribution"><span class="source">Darrin Wang</span></span>
</figcaption>
</figure>
<p>The <a href="http://www.iioa.org/files/conference-2/274_20110505091_GlobalMRIO_20110502.pdf">Eora project</a> has recently gone live to a limited set of specialists. This is a fully integrated global model revealing the carbon intensity of millions of production chains, showing each economy in detail with full adjustments made for international trade flows. So the time of “knowing nothing” or “it being too hard” is nearly over.</p>
<h2>How does it work for houses?</h2>
<p>The late <a href="http://www.tandfonline.com/doi/abs/10.1080/096132100368957">Graham Treloar</a> and colleagues at Deakin University used this “environmentally extended input-output analysis” to explore the physical intensity of construction types and the lifestyles lived therein. </p>
<p>Their work used energy units (gigajoules or GJ) to separate out the one-off or embodied cost of house building, and the recurring yearly operational costs of keeping it going. These can easily be converted to tonnes of carbon. Brown coal electricity and gas still rule in Victoria where the study was based.</p>
<p>The full life cycle picture of a building’s 30-year life with its occupant’s comings and goings provide messages critical to today’s carbon policy angst. For the full family energy budget of 100% over 30 years, the house build was 8% and operational energy (gas and electricity) took 22%. </p>
<p>Then come the interesting bits: personal belongings (2%), consumables (34%), financial services (8%), motor cars (22%) and holidays (4%).</p>
<p>The house build in the Treloar study was 1441 GJ embodied energy. Recurring energy was 3099 GJ over 30 years, with heating using 1440 GJ, appliances 643 GJ, hot water and cooking 613 GJ and lighting 402 GJ. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/8192/original/4jvfmc7j-1330479168.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/8192/original/4jvfmc7j-1330479168.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/8192/original/4jvfmc7j-1330479168.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/8192/original/4jvfmc7j-1330479168.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/8192/original/4jvfmc7j-1330479168.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/8192/original/4jvfmc7j-1330479168.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/8192/original/4jvfmc7j-1330479168.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">Investigate your appliance’s emissions.</span>
<span class="attribution"><span class="source">trekkyandy/Flickr</span></span>
</figcaption>
</figure>
<p>The 7-10 star designs now available could easily halve each recurring energy cost with solar passive design, triple glazed windows, solar hot water and plantation wood pellets for heating. </p>
<p>Decarbonising the electricity supply by photvoltaics or purchasing green power can help us get closer to the zero-carbon ideal. Renewable electricity does cost carbon: around 30 grams per kilowatt hour for wind and 100 gm/kWh for photovoltaics. Compare these to Victorian brown coal electricity at 1300 gms/kWh and then suburb-wide implementation gives substantial progress. </p>
<p>Decarbonising the embodied energy of the house build is more difficult and requires industrial processes to radically revamp. But even in Australia you can source good recycled product or aluminium made with hydropower rather than subsidized brown and black coal electricity.</p>
<h2>An efficient house is a nice start, but you need to buy less stuff</h2>
<p>Ministers for Climate Change run a mile from dealing with the carbon involved in consumables. </p>
<p>Today we churn through more stuff than in 2000, when Treloar’s study was done, so the figure of 2% for long-lived belongings may be a bit low. But the general premise if you want to lower emissions is to buy well and keep it for a long time. </p>
<p>A commonly purchased laptop computer has CO₂ emissions of 270 kg embodied in its manufacture and another 120 kg for the rest of its life emissions. So if fashion fads rule your life (or if, like my daughter, you drop your iPhone frequently) it all adds up.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/8195/original/b98fvtbz-1330479701.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/8195/original/b98fvtbz-1330479701.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/8195/original/b98fvtbz-1330479701.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/8195/original/b98fvtbz-1330479701.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/8195/original/b98fvtbz-1330479701.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/8195/original/b98fvtbz-1330479701.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/8195/original/b98fvtbz-1330479701.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Don’t try to own everything.</span>
<span class="attribution"><span class="source">pietriozzo/Flickr</span></span>
</figcaption>
</figure>
<p>Consumables at 34% (food, drinks, books, clothes and so on) are a large part of the energy inventory and thus carbon costs. But spending is what keeps the economy going, bankers happy and treasurers pontificating. </p>
<p>Our work shows that the more we spend the more we emit across <a href="http://ses.library.usyd.edu.au/bitstream/2123/2104/1/WaterWindCh9Dey.pdf">the whole life cycle</a>. This is clearly mapped in the Australian Conservation Foundation’s <a href="http://202.60.88.196/consumptionatlas/">Consumption Atlas</a>. </p>
<p>This atlas shows those leafy suburbs with high house prices emit on average two to three times per capita more than their poorer cousins on the city boundaries. So here a tension emerges between the hard slog of house design (where construction and materials plus operational energy equals 30% of the full 30 year life cycle) and the equivalent loading that comes from buying consumables. </p>
<p>The economy relies on shopping churn to keep optimism, maintain full employment, keep economic growth trundling along and our landfills overflowing. So unpalatable though it might be, the zero-carbon house requires a low-spend lifestyle to reap a double carbon dividend. Perhaps those triple glazed windows and photovoltaic panels will leave homebuilders financially stretched enough to make shopping even more painful.</p>
<h2>Why not walk to the shops?</h2>
<p>Motor cars are energy guzzlers and represented 22% of the household’s total lifecycle energy in this study. Each car has a manufacturing embodied energy cost of around 130 GJ and uses at least 100 GJ of fuel yearly. </p>
<p>Hybrids or small light cars which reduce fuel use by 50-70% are no brainers (and you should keep them going for ten years if possible). Focused <a href="http://www.sciencedirect.com/science/article/pii/S0967070X10000570">life cycle analyses</a> show that hybrids outperform conventional petrol and diesel cars across all impact categories by 50-90%, except that a hybrid’s waste streams are higher due to end of life treatment of batteries. Again a fuller decarbonisation is impossible unless the production chains for liquid fuels or electricity are themselves fully decarbonised.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/8194/original/3dvnyxf5-1330479524.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/8194/original/3dvnyxf5-1330479524.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=896&fit=crop&dpr=1 600w, https://images.theconversation.com/files/8194/original/3dvnyxf5-1330479524.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=896&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/8194/original/3dvnyxf5-1330479524.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=896&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/8194/original/3dvnyxf5-1330479524.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1126&fit=crop&dpr=1 754w, https://images.theconversation.com/files/8194/original/3dvnyxf5-1330479524.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1126&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/8194/original/3dvnyxf5-1330479524.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1126&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Living close to public transport really helps.</span>
<span class="attribution"><span class="source">Ben Cumming</span></span>
</figcaption>
</figure>
<p>More recent research <a href="http://www.tandfonline.com/doi/abs/10.3763/asre.2009.0052">by Peter Newton</a> and colleagues at Swinburne University focused on a house’s gadgets and their carbon impacts; that is, the yearly recurring carbon costs. “Walk up” medium density housing is better than apartment blocks and detached houses. It should have gas-boosted solar hot water (500 kg CO₂ per year), the basis set of appliances with a “best of breed” energy rating (3000 kg CO₂ per year), gas cooktop and oven and microwave (300 kg CO₂ per year), compact fluorescent or LED lighting (400 kg CO₂ per year) and gas heating (2000 kg CO₂ per year). </p>
<p>This six tonnes or so of operational emissions can be partially offset by 4000 watts or more of photovoltaic panels. But remember this is less than 30% of the household’s carbon loading, so the main job is yet to be embraced.</p>
<h2>Five evidence-based steps to living lightly</h2>
<p>So there are five take-home messages from using whole-economy principles for greenhouse accounting:</p>
<ol>
<li><p>Build the house properly to more than 7 star standards and trade off space and opulence for year-round comfort and low running costs.</p></li>
<li><p>Populate this house with the “best of breed” appliances and change behaviours of using and consuming. Focus on high quality goods that last forever and transcend fads.</p></li>
<li><p>Become a low-consumption and high-savings household, investing in safe buffers for your family’s future. Spend time together rather than buying stuff.</p></li>
<li><p>Consume mostly fresh non-processed foods grown within your state and region.</p></li>
<li><p>Live close to public transport, walk and cycle. Use the car sparingly, keep it for ten years and buy a hybrid if you have the cash.</p></li>
</ol><img src="https://counter.theconversation.com/content/5623/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>In previous research placements Barney Foran has received funding grants from many government and non-government research agencies. Currently there is no contracted research.</span></em></p>Recent articles on low carbon homes and life cycle measurement difficulties left carbon groupies concerned about the complexity involved in measuring our emissions. Measuring emissions isn’t as hard as…Barney Foran, Adjunct Research Fellow, Institute for Land, Water and Society, Charles Sturt UniversityLicensed as Creative Commons – attribution, no derivatives.