Want to Save the Planet? Go Vegan, Study Says

Scientists have produced the most detailed analysis yet on how farming damages the planet. Getty Images

Adopting a vegan diet (free from animal products such as dairy, eggs and meat) is the best way to protect the planet, according to a major new study.

By carrying out the most comprehensive investigation yet into the environmental impact of food production, researchers found that even buying sustainably sourced meat or dairy didn't outdo the benefits of a plant-based diet. And unless there is a major change in how animal products are cultivated and manufactured, eating vegan food will be better for the planet in the foreseeable future than farmers tinkering with their methods.

In the U.S., where meat consumption is per capita three times the global average, the adoption of plant-based diets could cut food emissions by between 61% to 73%. And the worldwide adoption of vegan eating would reduce global agricultural land by around 3.1 billion hectares, or almost three quarters.

"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," Joseph Poore of the Department of Zoology and the School of Geography and Environment, Oxford University, and co author of the study published in Science, told Newsweek. He also highlighted that food is not just an issue for green-house gas emissions but causes almost all of the world's major environmental issues.

"As an individual, you can have that impact today—not 20, 50 or 100 years into the future when it might be too late," he said.

Even a slight change in what we eat can have a big impact on the environment, the study showed. In lieu of a vegan diet, cutting down on animal products by half worldwide and not buying from high-impact producers would achieve 73% of the reduction in emissions of an entirely plant-based diet, according to the researchers. And lessening the consumption of oils, refined sugar, stimulants, and alcohol by a fifth would slash greenhouse gas emissions created by these products by 43%.

If consumers ditched the most impactful meat and dairy products in favor of plant-based foods, the environment would reap rewards equivalent to two-thirds seen in stopping meat and dairy production altogether. Clearer labeling and tax breaks on certain products could help consumers make more informed choices, the authors suggest.

The study also uncovered huge differences in the environmental impact of the same types of food. High-impact beef, for instance, produced 12 times more CO2 equivalents and used 50 times more land per 100 grams of protein than low-impact beef. But compared to pea growers, low-impact beef farmers used 36 times more land and emitted six times more emissions. Meanwhile, high-impact rice created 500% more green house gas emissios than low-impact variants, and a cup of coffee can create as little as 80g of CO2 or as much as 1.3kg, depending on production methods.

Aquaculture practices, which involve animals in ponds or nets typically fed with crops or by-products which are widely believed to be more environmentally friendly than land-based farming, created more methane and greenhouse gases than cows per kilogram of liveweight.

A small number of the producers were responsible for the majority of the environmental impact. For instance, 15% of beef production uses around 950 million hectares of land globally, and creates around 1.3 billion tonnes of CO2 equivalents. Beef can create 25,000% higher greenhouse gas emissions and use 11,000% more land than legumes, the study showed.

Producers can reduce their impact by adopting new technologies, but this can only go so far, the researchers said. For instance, a low-impact liter of cow's milk creates double the emissions and uses almost two times as much land as the same amount of soy milk.

To understand the environmental impact of the specific food products and the global farming industry, Poore and Thomas Nemecek of the Swiss agricultural research institute, Agroscope, analyzed 570 studies tracking the field-to-fork journeys of 40 different foods. The study involved data on over 38,000 farms and 1,600 processors, packaging types and retailers across 123 countries.

The researchers looked into the land and water use, greenhouse gas emissions, as well as ocean acidification and eutrophication caused by the 40 different products. They noted that there are currently more than 570 million farms producing crops across the world.

"Two things that look the same in the shops can have very different impacts on the planet," Joseph Poore said in a statement.

"Food production creates immense environmental burdens, but these are not a necessary consequence of our needs. They can be significantly reduced by changing how we produce and what we consume."

Dr Peter Alexander, lecturer in Global Food Security at the University of Edinburgh who was not involved in the study, told Newsweek that the findings are "extremely comprehensive" and "highly impressive."

The study doesn't take into account the environmental benfits of managed grazing, and the positive cultural and social outcomes of livestock production and consumption, he argued.

"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.

This piece has been updated with background information on aquaculture.

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