Meat Consumption in U.S. Cities Produces as Much Climate Pollution as Powering Homes

America’s city dwellers produce similar levels of greenhouse gas emissions when they eat meat and power their homes, a new study published in Nature Climate Change suggests. The study looked at over 3,500 U.S. cities, including Atlanta and Washington D.C., and found that the greenhouse gas emissions produced by urban dwellers eating beef, chicken and pork are larger than the entire carbon footprint of Italy, and similar to the emissions that come from powering American city homes.

Despite the similar climate cost of urban home emissions and meat consumption in those homes, much less attention is paid to reducing meat consumption, says one of the study’s lead authors and assistant professor at Michigan’s School for Environment and Sustainability, Benjamin Goldstein.

One reason for that, Goldstein told Sentient in an email, is that it is much easier “for designers, policymakers, and city-dwellers to focus on changing the hard infrastructure within the city, since they have direct control over these systems.”

Making changes to food systems and dietary habits is far more complicated. “The supply chains that support urban food systems are abstract and unseen,” Goldstein writes. Most of the meat consumed inside these large cities is produced outside of it, creating a kind of ‘out of sight, out of mind’ effect for consumers. For policymakers, Goldstein writes, this “spatial disconnect makes it challenging to think of these impacts when considering urban sustainability strategies.” All of that makes food emissions “much tougher to tackle,” he writes.

Globally, the food system generates about one third of total human-made greenhouse gas emissions and, according to one study, the production of meat and other animal-sourced foods makes up about 57 percent of that. The same study finds that within the animal protein category, beef is the largest contributor to climate change, generating about 25 percent of total food emissions.

In the new Nature study, to measure the meat emissions produced by cities, the researchers used and expanded an existing food-system supply-chain model, known as FoodS, to reconstruct meat supply chains by linking 3,143 feed-, livestock- and poultry-producing counties to 3,531 meat-consuming cities.

The study found that the total climate impact for U.S. cities is 329 megatons of CO2 equivalent, while the total emissions that come from using fossil fuels to light, heat, cool and power appliances in U.S. city homes is 334 megatons.

The study also modeled a number of ways to shrink urban food-related emissions, including reducing food waste, substituting beef with lower-emission meats or skipping meat once a week. The most impactful, the study finds, would see urban dwellers swapping half their beef for chicken, which would reduce emissions by 33 percent. Swapping half of beef consumption for a combination of pork and chicken reduces emissions by 29 percent, while not eating meat one day a week offers a 14 percent reduction.

Substituting chicken for beef can help lower grocery bills, the study authors argue, “and can be implemented more swiftly than some city decarbonization strategies.”

Goldstein argues meat substitution is also a more realistic strategy than asking people to eat less or no meat. “I have written multiple papers about switching to vegetarian diets … most people do not seem ready to adopt a no-meat diet, so it doesn’t feel viable at the moment,” he writes. “If we can curb GHGs from meat … and still allow people to eat a burger once a week, that is better in my opinion than asking people to go vegan and seeing no change at all.”

Switching from beef to pork or chicken is a clear improvement for emissions, but evaluating the proposed solution becomes murkier when you factor in animal welfare and other environmental metrics, like water pollution.

Advocates for farm animals have long decried what is sometimes described as the small body problem — meaning more smaller animals, like pigs, chickens and fish, must be raised and killed to replace larger ones like cows.

Animal welfare conditions for poultry chickens are also some of the worst in the food system. Smaller animals are generally lower in emissions, but meanwhile a 2018 paper found that there are other environmental consequences of pork and chicken production — including higher risks of acidification and eutrophication, both of which degrade water quality and soil health.

That acidification and eutrophication, says Richard Twine, a sociologist who studies interactions between animals, the environment, climate change and gender studies at the UK’s Edge Hill University, often manifests as polluted waterways. “I’m thinking about the well-documented cases of water pollution from the pork industry in places like North Carolina and, in the UK, obviously, the very famous case of the River Wye and all the concentration of chicken production” in the area.

Another criticism often levelled at this kind of consumer-oriented solution, says Twine, is that livestock producers are not held to account. “There’s no responsibility being placed upon producers to achieve a transition to a sustainable diet,” he says. It’s not as if we’re talking about linking city consumption with “nice family farms in the countryside. It’s huge meat corporations. And we need to be really realistic about their responsibility to make changes.”

Despite these criticisms, Twine says the study is valuable, particularly the “granularity of it, getting into those details of the relationships between urban and rural,” consumption and production.

Valuable too, he says, is the information it provides to individual cities about their dietary emission impacts. “Generally, it’s great to see that kind of research being done. And we probably need that research duplicated in other countries.”

The study also finds that emissions from transportation are a small fraction of overall livestock emissions, as has been shown in other research. For consumers eager to make a dent in their own climate emissions from what they eat, that means that eating locally, while appealing, does not in fact have much impact on emissions.

“Food miles and related emissions are largely a myth,” Goldstein writes to Sentient. “Emissions from transporting food account for around 10% of total emissions related to producing and distributing food products to retail.” By and large, he adds, “most emissions occur during production, especially in the case of meat which requires lots of feed and generates lots of on-site emissions” that come mainly from enteric fermentation, primarily cattle burps, and the manure lagoons used to hold animals’ urine and feces.

Highlighting the similarity between energy and food-related emissions could help people work on reducing the impact from what they eat, Twine says, in the same way they think about needing to switch off lights when they leave a room.

For Goldstein, the hope is that “our paper shows that the climate impacts of meat consumption can be a significant driver of a city’s carbon footprint, thereby starting a broader dialogue through the media and other channels about how to tackle the hoofprint.” These actions, he says, could build on existing efforts to decarbonize food systems or promote alternative protein sources in cities like New York and Los Angeles.

Another approach might be to expand Meatless Mondays to Tuesdays and even Wednesdays, which, Goldstein agrees, would triple the 14 percent emissions saved each day to a more substantial 42 percent.