Eliminating all animal agriculture within the next 15 years would not only drastically reduce greenhouse gas emissions, but actually pull carbon dioxide out of the atmosphere as grazing land returns to its natural vegetated state. (iStock image)
A new study of the climate impacts of raising animals for food concludes that phasing out all animal agriculture has the potential to substantially alter the trajectory of global warming.
The work is a collaboration between Michael Eisen, professor of molecular and cell biology at the University of California, Berkeley, and Patrick Brown, professor emeritus of biochemistry at Stanford University and the CEO of Impossible Foods Inc., a company that sells plant-based meat substitutes.
Eisen, who consults for Impossible Foods, and Brown used a simple climate model to look at the combined impact of eliminating emissions linked to animal agriculture and of restoring native vegetation on the 30% of Earth’s land surface currently used to house and feed livestock.
They found that the resulting drop in methane and nitrous oxide levels, and the conversion of 800 gigatons (800 billion tons) of carbon dioxide to forest, grassland and soil biomass, would have the same beneficial impact on global warming as cutting annual global CO2 emissions by 68%.
“Our work shows that ending animal agriculture has the unique potential to significantly reduce atmospheric levels of all three major greenhouse gases, which, because we have dithered in responding to the climate crisis, is now necessary to avert climate catastrophe,” said Eisen, who is also a Howard Hughes Medical Institute (HHMI) investigator at UC Berkeley.
A major reason for the large long-term effect Eisen and Brown observe is that its benefits accrue rapidly. Brown argues that this demonstrates that eliminating animal agriculture should be as high a priority as eliminating fossil fuel use.
“Eliminating animal agriculture would have a quicker and greater impact over the next 20 to 50 years, the critical window for avoiding climate catastrophe, and thus should be at the top of the list of potential climate solutions,” Brown said.
“There is,” he added, “an enormous, previously unrecognized opportunity to sharply bend the trajectory of climate change within a couple of decades, with multiple additional environmental and public health benefits, and minimal economic disruption.”
The study was published Feb. 1 in the journal PLOS Climate.
Not an impossible task
Eisen and Brown have discussed the impacts of raising animals for food for years. Both men are vegans. Eisen stopped eating meat after convincing himself of the dire impact animal agriculture has on the world’s climate. Brown founded Impossible Foods in 2011 for similar reasons, began marketing the Impossible Burger in 2016, and recently launched plant-based chicken nuggets and ground pork products.
Compared to business as usual, phasing out animal agriculture over a period of 15 years would, by reducing methane, carbon dioxide and nitrous oxide emissions and revegetating rangeland, pause the rise of greenhouse gases warming the climate until about 2060. This would mean that everyone on the planet would adopt a plant-only diet (lower dotted line. (Chart courtesy of PLOS Climate)
“My awareness of the potential impact was a major motivation for launching Impossible Foods,” Brown said. “In fact, I’ve been saying for years that replacing livestock in the global food system would turn back the clock on climate change. But although I knew that this conclusion was directionally correct, the environment and policy community would accept it only if we did this rigorous modeling that Mike and I did.”
Most research on the impact of animal agriculture has focused on the impact today of methane emissions from animals and their manure, nitrous oxide from fertilizer used to grow animal feed, and from the carbon dioxide produced raising and transporting animals and meat. Two reports within the past year, however, addressed a different aspect of animal agriculture: the potential that grazing land has for regrowing vegetation and sequestering carbon from the atmosphere.
“Everybody knows that methane is a problem. Everybody knows that livestock contribute to global warming in some way,” Eisen said. “But animal ag contributes to global warming in two ways: It contributes via emissions and contributes because that land would otherwise be holding carbon. Most analyses only look at one of those things.”
Even though the animal industry today is responsible for about 16% of annual greenhouse gas emissions, by some estimates about one-third of all the carbon dioxide humans have added to the atmosphere since the dawn of animal husbandry is a result of land cleared for animal grazing and to grow feed or provide forage for animals used as food.
“What hadn’t been recognized is the much more impactful potential to unlock negative emissions by eliminating that industry,” Brown said.
The two scientists spent the pandemic years researching climate models and climate change literature to quantify the direct and indirect impact of eliminating animal agriculture worldwide. While cows and other bovids, like buffalo, represent about 80% of animal agriculture’s impact, they also considered the impact of pigs, chickens and other domesticated animals used for food, though not the world’s fisheries.
While both researchers would just as soon eliminate animal agriculture today, they chose a more realistic scenario: a phaseout over 15 years.
“A 15-year phaseout is not unrealistic — a lot of things happen on that timeframe,” Eisen said. “We went from having no cellphones to cellphones being ubiquitous in less time than that. It’s not that we’re saying we’re going to get rid of animal ag in the next 15 years, though that’s sort of the mission for Impossible Foods, but that is something we could do.”
Their conclusions are that a 15-year phaseout would immediately eliminate about one-third of all methane emissions globally and two-thirds of all nitrous oxide emissions, allowing the atmosphere to achieve a new equilibrium at lower levels of both.
Better nutrition without animal products
While Eisen and Brown acknowledge that animal products are key to nutrition in most countries — they supply about 18% of the calories, 40% of the protein and 45% of the fat in the human food supply — they point out that worldwide, about 400 million people already live on entirely plant-based diets. Existing crops could replace the calories, protein and fat from animals with a vastly reduced land, water, greenhouse gas and biodiversity impact, requiring only minor adjustments to optimize nutrition.
Based on his experience with Impossible Foods, Brown said, “there’s compelling evidence that animal agriculture can be replaced without requiring meat lovers to compromise on nutrition or any of the sensory pleasures they love.”
Both scientists hope that their study will prod policymakers to consider the reduction or elimination of animal agriculture — barely mentioned in the most recent IPCC (Intergovernmental Panel on Climate Change) report — as an important option for reducing greenhouse gases. They look forward to a robust debate now that their data and analysis are online through the open access journal PLOS Climate.
“What we really did in the paper was try to formalize what it would mean to get rid of animal agriculture without making it too complicated,” Eisen said. “There’s a lot of uncertainty, there are a lot of unknowns, but I think probably the biggest uncertainty is whether people will look at this potential and act on it as a society.”
“I’m hoping that others, including entrepreneurs, scientists and global policymakers, will recognize that this is the most important opportunity humanity has to reverse the trajectory of climate change, and seize it,” Brown said.
The study was conducted with no outside funding. Eisen worked on the project as an HHMI investigator, alongside his research on gene regulation in fruit flies.
“I think this is a kind of Pearl Harbor moment for science. The climate of the planet is under a bigger threat now than it’s ever been in history, and to the extent that scientists can find ways to contribute, I think it’s really incumbent upon us to do so,” Eisen said.
RELATED INFORMATION
FAQs
Eating less meat can help reduce pressure on forests and land used to grow animal feed, which in turn protects biodiversity, the earth's ecosystems, and people living in poverty who are bearing the brunt of climate change. Eating less meat means eating foods that are plant-based rather than those that are animal-based.
How much would giving up meat help the environment? ›
Not only does a meat-free diet reduce Methane emissions, but it also reduces air pollution which is responsible for millions of premature deaths every year and fueling Climate Change. As such, “to combat the climate emergency and help protect our environment, we all need to reduce the amount of food we waste” [6].
How is global meat production impacting the environment? ›
There are three big environmental issues with the production of meat - feed sourcing, manure processing, and climate change. Raising meat takes vast quantities of feed. Millions of acres have been plowed over for large, monoculture crop fields dedicated to feeding livestock.
Is meat production bad for the planet? ›
Meat production accounts for 57 percent of the greenhouse gas emissions of the entire food production industry. It also results in widespread deforestation and loss of biodiversity, and each of these means that it significantly contributes to climate change.
What would happen to the planet if everyone stopped eating meat? ›
Would they overrun the planet? Billions of farm animals would no longer be destined for our dinner plates and if we couldn't return them to the wild, they might be slaughtered, abandoned, or taken care of in sanctuaries. Or, more realistically, farmers might slow down breeding as demand for meat falls.
What would happen if we reduced meat consumption? ›
It's rich in fiber, vitamins and other nutrients. And people who don't eat meat, called vegetarians, generally eat fewer calories and less fat. They also tend to weigh less. And they have a lower risk of heart disease than nonvegetarians do.
Is meat the biggest contributor to climate change? ›
With 99.48 kilograms of carbon dioxide equivalents per kilogram, beef production remains the biggest source of greenhouse gases. This is more than double the carbon dioxide equivalents per kilogram linked to lamb and mutton production (39.72 kilograms).
Why is meat free better for the environment? ›
By choosing a vegetarian diet instead of one loaded with animal products, individuals can dramatically reduce the amount of land, water, and oil resources that they consume and the amount of pollution they otherwise might cause.
How much does not eating meat reduce your carbon footprint? ›
When you take into account meat's entire lifecycle, each meat eater is responsible for 1.5 more tons of greenhouse gases than a vegan per year, according to a study by the University of Chicago. By contrast, switching from a Toyota Camry to a hybrid Toyota Prius would save one ton of greenhouse gases annually.
How much does the meat industry affect the environment? ›
Animal agriculture, in particular meat production, can cause pollution, greenhouse gas emissions, biodiversity loss, disease, and significant consumption of land, food, and water.
The production, wholesale and retail sectors, defi ned as the direct industry, combine for a total of 2.1 million jobs, generating $68 billion in wages and providing more than $278.9 billion in total economic output.
What can we do to reduce meat production? ›
Reducing Emissions from Beef Production: Improving Practices and Technologies
- Improve efficiency and productivity. ...
- Reduce enteric methane emissions. ...
- Improve manure management. ...
- Stabilize and sequester carbon in vegetation and soils. ...
- Engage with suppliers to reduce emissions across beef supply chains. ...
- Shift suppliers.
How does beef production cause greenhouse gas emissions? The short answer: Through the agricultural production process and through land-use change. The longer explanation: Cows and other ruminant animals (like goats and sheep) emit methane, a potent greenhouse gas, as they digest grasses and plants.
Is eating meat worse for the environment than being vegetarian? ›
The recent rigorous report by the EAT-Lancet Commission recommends reducing our consumption of animal products to not only benefit human health, but the health of our planet. Even the “greenest” sources of meat still produce more greenhouse gases than plant-based proteins.
Which meat production method is healthier for the planet? ›
And the Frontiers in Sustainable Food Systems study found that plant-based meat's greenhouse gas emissions were 34 percent lower than farmed fish, 43 percent lower than poultry, 63 percent lower than pig, 87 percent lower than beef from dairy cows, and 93 percent lower than beef from beef herds.
Would humans have survived without meat? ›
Healthy adults are fully capable of eating and digesting meat. Still, nutritionally and biologically, you can live without it. That said, humans are social animals whose beliefs about eating meat also depend on their cultural and religious norms.
Can the world survive without meat? ›
Yes. The average modern human can survive without meat. However, they should keep certain nutrient needs in mind! Cutting out meat with nutrition in mind can be a learning curb.
Would the world survive if everyone was vegan? ›
If everyone were vegan, agriculture would need just a quarter of the land it uses today. Even a diet avoiding only meat from cattle and sheep would cut land use in half.
What would happen if Americans stopped eating beef? ›
Most crops also act as carbon sinks, so they reduce carbon dioxide in the atmosphere and they require less fertilizer, which is a large methane producer. In addition, without any meat consumption, the need for cropland for livestock feeding would be reduced, so deforestation practices would lessen significantly.
Is it better to eat less meat or no meat? ›
Reducing your meat intake is better for your health
The health benefits of reducing your meat consumption are significant. Eating less meat has been found to decrease the chances of developing certain cancers, heart disease, stroke, diabetes, kidney disease, liver disease or lung disease.
When it comes to environmental impact, beef is by far the worst offender compared to other proteins. But, that doesn't mean that cheese—or any dairy product—is in the clear. According to the Oxford study, “tenth-percentile GHG emissions and land use of dairy beef are then 36 and 6 times greater than those of peas.”
How much meat should you eat climate change? ›
According to research published in medical journal The Lancet, by 2050 each person should be eating no more than 300g of meat per week. That's equivalent to three chicken breasts or a very large steak. Sound manageable?
Which meat has the biggest environmental impact? ›
The worst types of meat for the environment include beef, lamb and mutton, pork, and also some farmed fish products. They are especially bad for the environment because of their land and water requirements alongside their greenhouse gas contributions and freshwater withdrawals.
Do vegans have a lower carbon footprint? ›
Many studies suggest that being vegan is one of the best things you can do to reduce your carbon footprint. But being vegan does not always have a lower carbon footprint. Vegan foods are not always better for the environment for 3 reasons: The transport of the food.
Does being vegan actually save animals? ›
Going vegan is one of the best things you can do to help stop animal cruelty. By refusing to pay for animal products, you reduce the demand for them, which ensures fewer animals are bred to suffer and die on farms and in slaughterhouses.
What is better for the environment vegan or meat? ›
Evidence shows that vegan diets tend to have far lower carbon, water and ecological footprints than those of meat- or fish-eaters. Although one Italian study found two vegan participants with extremely high eco-impacts, this turned out to be because they only ate fruit.
Which animal has the lowest carbon footprint? ›
Meat from small, non-ruminant animals, such as chicken, turkey, rabbit and duck, has a much lower GHG footprint than beef and lamb.
What meat has the highest carbon footprint? ›
#1 (highest): Bovine meat (beef herd)
Beef has the highest carbon footprint of any food. This is because of what is required to raise and farm cattle. Animals used for beef production require a tremendous amount of feed, which must be grown on its own.
Which meat has the lowest carbon footprint? ›
#1 Turkey and Chicken
These birds do not produce methane and need less food and water than sheep and cows. If you want to minimise your carbon footprint without giving up meat, chicken is your best option. Chicken produces 2.33 kg of C02 per kg of meat before transport and processing.
Is PETA against eating meat? ›
A hot topic in classrooms and on the minds of many people today is whether or not it's ethical to eat animals. Here at PETA, our core belief is that animals are not ours to use.
Meat consumption is highest across high-income countries (with the largest meat-eaters in Australia, consuming around 116 kilograms per person in 2013). The average European and North American consumes nearly 80 kilograms and more than 110 kilograms, respectively.
Why should we eat meat? ›
Meat and poultry are great sources of protein. They also provide lots of other nutrients your body needs, like iodine, iron, zinc, vitamins (especially B12) and essential fatty acids. So it's a good idea to eat meat and poultry every week as part of your balanced diet.
How much does the meat industry contribute to deforestation? ›
Beef is the #1 cause of deforestation
Today, 41% of global deforestation—and 80% of Amazon deforestation—is driven entirely by beef production. Over 33% of habitable land is already relegated to animal agriculture, and an area at least the size of Switzerland is razed each year.
Do poorer countries eat more meat? ›
People in developing countries currently consume on average one-third the meat and one-quarter of the milk products per capita compared to the richer North, but this is changing rapidly. The amount of meat consumed in developing countries over the past has grown three times as much as it did in the developed countries.
How much does the beef industry impact the US economy? ›
In 2022, cattle production is forecast to represent about 17 percent of the $462 billion in total cash receipts for agricultural commodities. With rich agricultural land resources, the United States has developed a beef industry that is largely separate from its dairy sector.
How eating less meat can reduce poverty? ›
The Impact of How Eating Less Meat Can Reduce Poverty
Consuming fewer animal products could reduce world hunger and poverty. The United Nations World Food Council estimates that transferring 10-15 percent of cereals fed to livestock to humans is enough to raise the world's food supply to feed the current population.
How does not eating meat affect climate change? ›
About 40 percent of greenhouse gases come from agriculture, deforestation and other land-use changes. Meat—particularly beef—drives climate change in two ways: first, through cows' emission of methane, a potent greenhouse gas, and second, by destroying forests as they are converted to grazing land.
How does reducing food waste help climate change? ›
And if food goes to the landfill and rots, it produces methane—a greenhouse gas even more potent than carbon dioxide. About 6%-8% of all human-caused greenhouse gas emissions could be reduced if we stop wasting food.
How does beef farming affect climate change? ›
Raising animals on farms for food production takes a tremendous toll on the health of the environment. Animal agriculture is a contributor to greenhouse gas emissions, including nitrous oxide and methane, water pollution and the destruction of forests and other wild areas that help to regulate the planet's atmosphere.
Is it better for the environment to eat meat or fish? ›
Seafood has a much lower impact on space and freshwater than land-based food. In addition to being one of the most carbon-efficient foods on the planet, wild-caught fish require no land, no freshwater, and has a much lower impact on wildlife—no marine fish has ever gone extinct due to fishing.
Chicken. Environmental Working Group (EWG), researchers found chicken is the most sustainable choice out of all the different types of meat. "Certified Humane" or "Animal Welfare Approved" logo to ensure the animals are receiving the best possible care and treatment.
Is lab-grown meat 25 times worse for the environment? ›
One of the authors of the study, Edward Spang from UC Davis, said lab-grown meat isn't on the market in the United States yet, but there are things to consider before mass production. The study by UC Davis found the global warming potential to be four to 25 times greater than regular beef.
What is the least cruel meat to eat? ›
Choose welfare-certified chicken and pork over beef and lamb. Source seafood that was farmed using sustainable fishing practices. Reduce how much meat, dairy and fish you eat overall.
Why is it important to reduce meat consumption? ›
Eating less meat improves your health
From reduced cancer rates and heart disease, to an increased overall lifespan, consuming more plant-based foods will improve your own health, and the health and wellbeing of your community.
What are the benefits of reducing animal products? ›
Reducing meat consumption may improve human health, curb environmental damage and greenhouse gas emissions, and limit the large-scale suffering of animals raised in factory farms.
Does reducing meat consumption reduce water pollution? ›
A meat-free diet can cut our water footprint in half! Studies show that a healthy meat-free diet reduces our water footprint by up to 55%.
How does meat consumption affect climate change? ›
Verdict. The meat industry is responsible for a large share of global greenhouse gas emissions. It contributes not only to global warming but also causes direct environmental pollution. People who eat a lot of meat can help fight the climate crisis by reducing or quitting meat consumption altogether.
What are 3 reasons why meat is important in the diet? ›
Meat and poultry are great sources of protein. They also provide lots of other nutrients your body needs, like iodine, iron, zinc, vitamins (especially B12) and essential fatty acids. So it's a good idea to eat meat and poultry every week as part of your balanced diet.
How does reducing meat consumption benefit animals? ›
Eating less meat helps the environment because it lowers the demand for meat products, and in turn reduces the land use and environmental damage of the meat industry.
What is the importance of reduced meat and dairy consumption? ›
A 50% Drop In Meat and Dairy Consumption Prevents 1.6 Billion Tons of Greenhouse Gases. Replacing 50 percent of animal products in the U.S. diet with plant-based foods could prevent 1.6 billion tons of greenhouse gases (GHGs) from entering the atmosphere by 2030.
In fact, people who abuse animals are five times more likely to commit violent crime. Animal abuse, like many other forms of abuse, is about power and control over a helpless victim. By taking action against animal cruelty, we protect animals and may uncover and perhaps prevent additional crimes.
