According to a new study, a vegan diet is the “single biggest measure” that can be taken to reduce environmental pollution. Researchers at the University of Oxford found that not eating meat and dairy products can reduce a person’s carbon footprint by up to 73%.
If all people worldwide were to stop eating meat products, the area of land used for global agriculture could be reduced by around 75%. This would correspond to the combined size of the USA, China, Australia and the EU; such a reduction would lead to a significant decline in greenhouse gas emissions. The remaining agricultural land would be sufficient to feed the world’s population, according to scientists. The loss of natural habitat due to agriculture is the main cause of the current mass extinction of wildlife.
Animal-based food puts more strain on the planet than plant-based food
The new study, published in the scientific journal Science, is one of the most comprehensive analyses to date of the negative impact of agriculture on the environment. The study analyzed data from nearly 40,000 farms in 119 countries. The researchers examined a total of 40 agricultural products, which account for 90% of global protein and calorie consumption. The impact of these foods – from producer to consumer – on land use, greenhouse gas emissions, freshwater use and water and air pollution was comprehensively assessed.
The results show that the environmental impact of animal products significantly exceeds that of plant products. While global meat and milk production is responsible for 60% of agricultural greenhouse gas emissions, the products themselves account for only 37% of protein and 18% of calories in the diet.
The comparison of different techniques for producing the same food showed big differences in environmental impacts. For example, cattle reared on natural pastures consumed 50 times less land than those reared on deforested land. According to the study, the latter method can lead to up to 12 times more greenhouse gas emissions. These results are in stark contrast to the greenhouse gas emissions released by plant-based protein production for products such as tofu and peas.
Study leader stops eating animal products
According to Joseph Poore, research director and lead author of the study, a vegan diet is the best way to reduce an individual’s environmental footprint. The consumption of plant-based foods not only reduces greenhouse gases, but also global acidification, eutrophication, and land and water use.
The effect is “far bigger than cutting down on your flights or buying an electric car,” he explained, since the latter would only reduce greenhouse gas emissions. “Avoiding consumption of animal products delivers far better environmental benefits than trying to purchase sustainable meat and dairy,” he added in an interview with The Independent.
Poore also explained that even production methods considered sustainable, such as the production of meat from grass-fed cattle, can cause environmental problems. “Converting grass into [meat] is like converting coal to energy. It comes with an immense cost in emissions,” he told the Guardian.
Poore’s research is the result of a five-year project that began as an investigation into sustainable meat and milk production. The next step is to find ways to test his proposed approach in practice. The challenge, however, is implementation. Adding environmental labels to products would be insufficient. “Consumers take time to become aware of things, and then even more to act on them. Furthermore, the labels probably need to be in combination with taxes and subsidies. My view is that communicating information to consumers could tip the entire food system towards sustainability and accountability.”
After the first year of his research project, the Oxford scientist stopped eating animal products altogether. “These impacts are not necessary to sustain our current lifestyles. The question is by how much can we reduce them, and the answer is a lot.”
Original study: Poore J., Nemecek T. Reducing food’s environmental impacts through producers and consumers. Science. 2018;360:987–992.