Avoiding meat and dairy products is the single best way a person can reduce his or her environmental footprint, according to new research examining the impact of global food production.
In the most comprehensive study on the matter to date, scientists at the University of Oxford in the United Kingdom and Agroscope, an agricultural research institute in Switzerland, analysed data covering 40 different agricultural goods produced by more than 38,000 farms in around 120 countries. Together, the farms studied account for about 90% of the food that is consumed throughout the world.
Researchers examined a range of environmental factors, including greenhouse gas emissions, ocean acidification, water pollution and land and water use, and assessed the products’ impacts from farm to table.
The results, published on Friday in Science, showed that if meat and dairy consumption were eliminated, global farmland could be cut by more than 75% and still provide enough food for the world’s population.
“A vegan diet is probably the single biggest way to reduce your impact on planet Earth, not just greenhouse gases, but global acidification, eutrophication, land use and water use,” lead researcher Joseph Poore of Oxford’s School of Geography and Environment told The Guardian.
The analysis showed that meat and dairy have an outsized environmental impact compared to their contributions to a person’s diet. Although meat and dairy products provide only 18% of total calories and 37% of protein, they use 83% of farmland and account for 60% of the greenhouse gases emitted by agricultural activities, according to the study.
Researchers found that environmental impacts varied significantly within the same products. Raising beef cattle on deforested land, for example, generates 12 times the amount of greenhouse gases and uses 50 times more land than raising cattle in natural pastures.
“Two things that look the same in the shops can have very different impacts on the planet,” Poore said in a statement.
The study found that even sustainably produced meat and dairy products had a bigger environmental impact than plant-based products. “Impacts of the lowest-impact animal products typically exceed those of vegetable substitutes,” the study states. For example, even the lowest impact beef contributes six times more greenhouse gases and uses 36 times more land than plant proteins such as peas.
“At present, it’s better to change what you consume, rather than trying to purchase sustainable animal products. So plant-based diets are the best way to reduce foods impacts,” Poore told Newsweek.
However, the study showed that even small dietary changes can have a big impact. If consumption of animal products were reduced by half worldwide and consumers avoided buying products from high-impact producers, it would produce about 73% of the emissions reductions achieved by eating an entirely plant-based diet, reports Newsweek.
Dr Peter Alexander, a lecturer in global food security at the University of Edinburgh, told Newsweek that although the findings are “extremely comprehensive” and “highly impressive,” the results should be interpreted with care.
Dr Alexander, who was not involved in the research, argued that the study does not factor in managed grazing’s environmental benefits or livestock production and consumption’s positive cultural and social impacts.
“We should not interpret these results as the need to become vegan, but rather to moderate our consumption and seek a more equitable distribution of food that creates healthier diets for all,” he said.