Are Meat Eaters Contributing to Climate Change?

From the WebMD Archives

By Robert Preidt

HealthDay Reporter

WEDNESDAY, March 28, 2018 (HealthDay News) -- Climate change scientists have a beef with all the steaks and burgers Americans are eating.

Beef is a major source of greenhouse gas emissions associated with food production, the researchers said in a new study.

They found that one-fifth of Americans account for nearly half of all U.S. food-related greenhouse gas emissions that contribute to climate change.

And America's love affair with beef is the main reason, said Martin Heller, the study's first author.

"Reducing the impact of our diets -- by eating fewer calories and less animal-based foods -- could achieve significant reductions in greenhouse gas emissions in the United States," said Heller, a researcher with the University of Michigan School for Environment and Sustainability.

"It's climate action that is accessible to everyone, because we all decide on a daily basis what we eat," he added.

For various reasons, "the production of both beef cattle and dairy cows is tied to especially high emissions levels," Heller and his colleagues said in a university news release.

These bovines eat lots of feed that involves use of fertilizers and other substances manufactured through energy-intensive processes. There's also the fuel used by farm equipment.

"In addition, cows burp lots of methane, and their manure also releases this potent greenhouse gas," the researchers said.

Heller's team created a database on the environmental effects of producing more than 300 types of foods. They linked that to data on the diets of more than 16,000 U.S. adults.

The researchers found that on any given day, 20 percent of Americans were responsible for 46 percent of all food-related greenhouse emissions in the country. Those with the greatest impact were linked with eight times more emissions than those with the lowest impact.

Beef consumption accounted for 72 percent of the difference in greenhouse gas emissions between the highest and lowest groups, according to the study.

The researchers only looked at emissions from food production. Emissions from processing, packaging, distribution, refrigeration and cooking of food would likely increase total emissions by 30 percent or more, according to Heller.

"A big take-home message for me is the fact that high-impact diets are such a large part of the overall contribution to food-related greenhouse gases," Heller said.

If people in the highest impact group ate less meat and reduced their calorie intake, it would lead to a one-day reduction in greenhouse gas emissions equivalent to eliminating 661 million passenger-vehicle miles, according to the researchers.

If that diet shift were permanent and accompanied by similar changes in domestic food production, the United States would achieve nearly 10 percent of the emissions reductions called for under the Paris climate accord.

Even though the Trump administration said it will withdraw from the accord, many states and municipalities are still working to meet the emissions targets, the researchers noted.

The findings were published recently in the journal Environmental Research Letters.