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Published on January 13th, 2019 | by Carolyn Fortuna


Plant-Based Diets Can Make “A Huge Difference In Our Carbon Footprints” — #CleanTechnica Exclusive

January 13th, 2019 by  

Actors Joaquin Phoenix, Emily Deschanel, Woody Harrelson, Peter Dinklage, and Casey Affleck are in the cohort. So, too, are singers Carrie Underwood, Ozzy Osbourne, and Stevie Wonder. There’s former US President Bill Clinton, heavyweight boxing champ Mike Tyson, radio personality Don Imus (really?), and peace activist Thich Nhat Hanh. These prominent vegans are just a sampling of the half of one percent of the US population — or 1.62 million — who are vegan. Statistically, it’s a small percentage, yet their diets could be the single biggest way to reduce their environmental impact on earth.

Systemic change toward more plant-based diets is critical for avoiding catastrophic environmental damage, including climate change. Why? Animal food products that humans consumer contribute a large proportion of food system climate impacts. Of the various reasons to choose a largely vegetarian diet, the low efficiency of producing animal food in relation to the its contribution to greenhouse gas (GHG) emissions and the growing world population has moved it to the Top Reasons to Eat Plant-Based Foods.

In a recent CleanTechnica article, we looked at new momentum for a meat tax due to the environmental deterioration caused by cattle rearing and associated meat consumption. Some of the data for that article came from a study led by Dr. Marco Springmann, who is a Senior Researcher on Environmental Sustainability and Public Health at the University of Oxford. A global switch to diets that rely less on meat and more on fruit and vegetables could save up to 8 million lives by 2050, the study outlines.

As a result, “Analysis and Valuation of the Health and Climate Change Cobenefits of Dietary Change” concludes that it is necessary today to begin to include the social health cost of red and processed meat consumption in its pricing.

carbon footprints

Dr. Springmann offered CleanTechnica his insight into 3 different areas: meat reductions in light of COP24 climate talk recommendations, the balance of health and environmental effects of future plant-based diet scenarios, and appropriate taxation on the foods we eat to compensate for their social consequences.

Looking ahead after the 2018 UN Climate Talks

plant-based dietsThe Paris Climate Agreement acknowledges that keeping GHG emissions as close to 1.5C as possible and mitigating climate change impacts will require increased private and public funding commitments. In 2018, the United Nations’ Intergovernmental Panel on Climate Change estimated that to meet this target, the world community would need to double the pace of decarbonization planned under the agreement, with renewables supplying 72%-85% of electricity by 2050, requiring $2.4 trillion per year in clean energy investment through 2035.

CleanTechnica Question: In light of the COP24 climate talks in Poland and the agreement to implement the Paris agreement, how can reductions in animal consumption help now more than ever?

Dr. Springmann’s Answer: The food system is responsible for about a quarter of all greenhouse gas emissions, and the majority of those emissions (roughly three quarters) are due to animal products. Dietary changes towards more plant-based diets can therefore make a huge difference in our carbon footprints, and they might indeed be necessary in order to avoid dangerous levels of climate change and stay below a global warming of below 2 degrees Celsius.

plant-based diets

Finding the Balance amidst Strain on Global Food Systems

Global food systems are both influenced by and have an influence on health, economic development, and the environment. Springmann’s research into food for the future suggests that global food systems will face considerable strain over the coming decades as income growth, urbanization, and globalization lead to shifts towards Western dietary patterns — which are high in meat and processed foods — across the developing world. Under these conditions, the challenge is to find a sustainable method to feed the world’s increasing population while also considering the trade-offs and synergies between health, environmental sustainability, and economic development.

Q: What balance of health and environmental effects can emerge from a social shift toward more plant-based diets?

A: We estimated that changes towards more plant-based diets could reduce premature mortality by up to 20% by preventing many diet-related diseases, such as coronary heart disease, stroke, and cancer. In addition, such dietary changes would reduce the food-related emissions footprint one has by up to 3 quarters and also save significant amounts of agricultural land and freshwater that would otherwise be needed to produce animal feed.

plant-based diets

Appropriate Health and Environmental Taxation of Foods

Changing meat consumption habits is a challenge that requires identifying the complex social factors associated with meat eating and developing policies for effective interventions. Meat production is the single most important source of methane, which has a relatively high warming potential but a low half-life in the environment compared with that of CO2. Successful interventions to improve health and environmental objectives are likely to require that governments and other bodies to implement a suite of interventions to stimulate change.

Q: Would a meat tax contribute to such a shift, based on your research, and, if so, why?

A: At the moment, we are not paying for the health and environmental consequences of our consumption decisions. Emissions or health taxes on foods can address that and contribute to steer consumers towards healthier and more sustainable alternatives that then are relatively cheaper. We estimated that appropriate health and environmental taxation of foods would reduce consumption of beef and processed meat by several servings a week. And one could imagine even bigger reductions if the tax schemes were to be complemented by public information campaigns and changes in what is on offer in supermarkets and canteens. Important here will be to support low-income households by highlighting the many cheaper alternatives to animal products that are both healthier and more sustainable.

plant-based diets

Interested in the Method behind the Meat Reduction Research?

To obtain estimates of the total GHG emissions associated with each diet scenario, Springmann and the team of researchers multiplied commodity-specific gross consumption estimates (i.e. without deducting food waste) (measured in kcal/d/cap) by the corresponding emissions factors (measured in g/kcal) and population numbers, and converted the result to GHG emissions per region per year. They used the standard deviation reported in the meta-analysis (12) to calculate error bounds for their estimates. To account for future productivity improvements, they used the historical changes in GHG emissions intensity per change in output between 1961-2010 for beef, pork, poultry, eggs, dairy, and rice (excluding small absolute increases in the emissions intensity for wheat and maize) and applied those changes to the changes in production between the base year of 2005/07 and 2050.

The resulting reductions in GHG emissions intensity were 14.9% for beef, 5.8% for pork, 9.8% for poultry, 10.0% for eggs, 22.5% for dairy, and 6.2% for rice. For contextualization in terms of climate change, they calculated the ratio of food-related GHG emissions to GHG emissions from all sources. They used historical data for the base year 2005/07, and they adopted emissions estimates from the International Panel on Climate Change (IPCC) for an emissions pathway consistent with a likely (>66%) chance of limiting global temperature increase to below 2°C (32), an aim that was agreed to by the international community in 2010 as part of the Cancun Agreements to the United Nations Framework Convention on Climate Change.

plant-based diets

Final Thoughts

Today, food is a measure of both prosperity and healthfulness across social strata. As the authors of The China Study state, there are “multiple benefits of consuming whole, plant-based foods, and the largely unappreciated health dangers of consuming animal-based fords, including all types of meat, dairy, and eggs” (p. 14). In essence, not only is a plant-based diet that disdains processed food good for the planet, it is a smart diet.

Across a vast expanse of studies, methods, populations, and outcomes, an emphasis on vegetables and fruits is perhaps the most consistent feature of diets associated with favorable health outcomes. And now we have become quickly conscious — in light of the COP24 announcement that only a dozen or so years remain for us to get a global handle on carbon emissions or suffer catastrophic consequences — that what we eat is a significant contributor to GHG emissions. The Springmann, et al analysis suggests that, to achieve climate stabilization, a balance will need to be struck between the degree of adoption of plant-based diets, advances in mitigation technologies of the food sector, and disproportionate reductions in non–food-related GHG emissions.

Thanks to Dr. Springmann for taking the time to respond to our CleanTechnica inquiry. He is situated within the  Oxford Martin Programme on the Future of Food and the Centre on Population Approaches for Non-Communicable Disease Prevention with the Nuffield Department of Population Health.

Copyright-free images via Pixabay 


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About the Author

Carolyn Fortuna, Ph.D. is a writer, researcher, and educator with a lifelong dedication to ecojustice. She's won awards from the Anti-Defamation League, The International Literacy Association, and The Leavy Foundation. She’s molds scholarship into digital media literacy and learning to spread the word about sustainability issues. Please follow me on Twitter and Facebook and Google+

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