Updated May 19, 2019. Which diet is best for the environment? According to the most comprehensive analysis of farming’s impact on the planet, plant-based food is most effective at combatting climate change. Oxford University researcher Joseph Poore, who led the study, said adopting a vegan diet is “the single biggest way to reduce your impact on planet Earth.”
The study, which was published in the journal Science, analyzed the impact of various food industries on the planet by looking at data from around 40,000 farms in 119 countries.
Researchers studied 40 food products that account for 90 percent of total food consumed. The total environmental impact of these foods was assessed “from farm to fork,” The Guardian said, on the basis of land allocation, carbon emissions, freshwater usage, acidification (air pollution), and eutrophication (water pollution).
The research found that multiple environmental issues could be vastly improved by cutting meat and dairy consumption. Land use, for instance, could be reduced by more than 75 percent – an area equivalent to the U.S, European Union, China, and Australia – by removing these industries, whilst still feeding the world’s population.
Meat and dairy use most – 83 percent – of the world’s farmland. They also produce 60 percent of agriculture’s greenhouse gas emissions. Even though they drain most of the world’s resources, meat and dairy make up just 18 percent of the population’s calories and 37 percent of protein.
The researchers discovered that even the lowest impact meat and dairy products still harm the planet more than the least sustainable vegetable and cereal foods.
Speaking to The Guardian, lead researcher Poore said, “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.”
“It is far bigger than cutting down on your flights or buying an electric car,” he said, since these methods only cut greenhouse gas emissions. “Agriculture is a sector that spans all the multitude of environmental problems. Really it is animal products that are responsible for so much of this.”
Different farms have varying impacts on the planet, creating an opportunity to reduce harm, Poore said. If the most detrimental half of meat and dairy production was replaced by vegan foods, the planet would see two-thirds of the benefits of ridding all meat and dairy industries. However, updating farming practices is not cheap and different farms require different changes. “There are over 570m farms all of which need slightly different ways to reduce their impact. It is an [environmental] challenge like no other sector of the economy,” Poore said. However, he noted that the $500 billion that is spent every year on agricultural subsidies could go toward the improvement of these practices. “There is a lot of money there to do something really good with,” he said.
The Oxford researcher added that food labels detailing the environmental impact of the product could be also useful, helping shoppers make more eco-friendly choices. Subsidies for sustainable and healthy foods, as well as taxes on meat and dairy, would also be important. As well as alleviating some environmental pressure, meat taxes could benefit public health and the economy. Research from last year found that $285 billion in health care costs could be cut by introducing meat taxes, given that health-related costs directly linked to red and processed meat intake will reach this figure by 2020.
While introducing more sustainable farming practices could have some advantages, Poore noted that ditching animal-based foods altogether is far more effective than attempting to buy meat and dairy that is slightly better for the environment. “Avoiding consumption of animal products delivers far better environmental benefits than trying to purchase sustainable meat and dairy,” he said.
How Does the Food We Eat Impact the Planet?
Carbon emissions are to blame for one of Earth’s most critical issues: climate change.
As the urgency of the environmental crisis because more understood, experts are looking into the generators of greenhouse gas emissions and pinpointing animal agriculture as one of the leading contributors.
In September, the United Nations Environment Programme (UNEP) named meat “the world’s most urgent problem.”
“Our use of animals as a food-production technology has brought us to the verge of catastrophe,” UNEP said in a statement. “The greenhouse gas footprint of animal agriculture rivals that that of every car, truck, bus, ship, airplane, and rocket ship combined.”
“There is no pathway to achieve the Paris climate objectives without a massive decrease in the scale of animal agriculture,” it said.
Poore’s food analysis found that even the lowest impact beef generates six times more greenhouse gases than plant-based protein like peas. According to the research, beef creates up to 105kg of greenhouse gases to make 100g of meat, whilst tofu produces less than 3.5kg to make the same amount of food.
Grass-fed beef, believed to have a relatively low impact on Earth, still generates vastly more emissions than plant-based food. “Converting grass into [meat] is like converting coal to energy. It comes with an immense cost in emissions,” Poore stated.
In late 2017, researchers studied how much carbon pollution is generated to produce various foods. Like Poore’s research, they found that animal products are vastly worse for the planet than vegan food. Beef is the worst offender, generating 330g of carbon – the equivalent to driving a car three miles – to produce a single serving. However, the issue is not exclusive to cow meat. The study found that 52g of carbon dioxide is generated to make a serving of chicken, whilst cheese produces 74g. In contrast, plant-based foods like beans and lentils emit 1.9 grams and 2 grams of carbon respectively.
Speaking about the results, postdoctoral researcher Maya Almaraz commented, “A lot of people feel really helpless when it comes to climate change, like they can’t make a difference. And what our research is showing is that your personal decisions really can have a big impact.”
Seafood isn’t exempt from the issue either. Poore’s farming study uncovered a “surprising” discovery about the impact of freshwater fish farming on the planet, The Guardian said. The industry, which provides two-thirds of such fish to Asia and 96 percent to Europe, was considered “relatively environmentally friendly,” The Guardian commented, however the research proved otherwise.
Poore said, “You get all these fish depositing excreta and unconsumed feed down to the bottom of the pond, where there is barely any oxygen, making it the perfect environment for methane production.” Methane is one of the most potent greenhouse gases. It is around 30 times more potent as a heat-trapping gas than carbon dioxide.
Animal agriculture uses vast amounts of land compared to vegan food. Producing even the lowest impact beef requires 36 times more land than peas, commonly used as a key ingredient in products like vegan burgers.
The significant amount of land used for meat and dairy production raises multiple problems for the planet. Overgrazing is the major reason that one-third of the planet is desertified. Livestock and forage crops (crops grown especially for livestock to eat) are the leading contributor to rainforest destruction. Writing about the Amazon, the world’s largest tropical rainforest, Greenpeace said, “Cattle ranching is now the biggest cause of deforestation in the Amazon, and nearly 80 percent of deforested areas in Brazil are now used for pasture.”
“The impact this is having on the forest is huge – between 1996 and 2006, an area the size of Portugal was carved out for cattle ranching,” it said. Greenpeace also pointed out the social problems attached to the industry. “Cattle ranching has the highest rates of slave labour in Brazil – just over 3,000 people held as slaves were freed from ranches last year,” it said in 2009.
A plant-based diet is also best in terms of water use, according to a growing bank of research. As countries around the globe struggle with low water levels and droughts, experts urge for the public to be more mindful of their water usage. Environment-focused website Water Calculator says that the largest contributor to an individual’s water footprint comes from their diet. “In order to lower water footprints, there’s no better place for a person to start than taking a closer look at their food choices,” it writes, adding that ditching meat is “the best way to lower dietary water footprints.”
“Beef has a particularly high water footprint at about 1,800 gallons per pound, while pork follows at 578 gallons and chicken with 468 gallons,” Water Calculator says. “On average, the water footprint of a vegan or vegetarian is around half that of a meat eater.”
The statements have been backed up by other studies. Research from 2018, which was the most detailed nationwide study on food consumption and water footprints ever, found that vegan food carries the smallest water footprint, uncovering that a plant-based diet uses five times less water than a meat-based one.
The leading cause of the current mass extinction of wildlife is habitat destruction, caused by the agriculture industry, The Guardian said.
In October 2017, it was reported that humanity’s appetite for animal protein was sending multiple animal species to extinction. The World Wildlife Foundation (WWF) reported that producing forage crops places an “enormous strain on our natural resources and is a driving force behind wide-scale biodiversity loss.” The UK’s eating habits are directly linked to the extinction of 33 species in the UK and abroad, the WWF said.
Also in 2017, The Independent reported that industrial farming is driving the sixth mass extinction of life on Earth. The last mass extinction, which ended the existence of dinosaurs and more than three-quarters of all life, occurred 65 million years ago and was caused by an asteroid strike. The current mass extinction is being driven by the production of soy crops grown to feed livestock, palm oil, and ocean dead zones, caused by fertilizer runoff from farms.
The Future of Farming
Poore’s farming analysis is a vital contribution to the discussion about the modern food system. Prof Tim Benton, from the University of Leeds in the UK, said to The Guardian, “This is an immensely useful study. It brings together a huge amount of data and that makes its conclusions much more robust. The way we produce food, consume and waste food is unsustainable from a planetary perspective.”
“Given the global obesity crisis, changing diets – eating less livestock produce and more vegetables and fruit – has the potential to make both us and the planet healthier,” Benton said.
While some, like the University of Edinburgh’s Dr Peter Alexander, insisted that the research doesn’t raise “the need to become vegan overnight, but rather to moderate our [meat] consumption,” Poore maintains that humankind can and should do better.
“The reason I started this project was to understand if there were sustainable animal producers out there,” he said. “But I have stopped consuming animal products over the last four years of this project. These impacts are not necessary to sustain our current way of life. The question is how much can we reduce them and the answer is a lot.”