Many people still seem surprised to learn that methane emissions from cows are a major contributor to climate change. But now, a new study has revealed that meat-heavy diets account for almost half of the food-related greenhouse emissions in the United States.
Researchers from the University of Michigan and Tulane University examined the carbon impact of typical diets in the United States and found that just 20 percent of Americans are actually responsible for half of diet-related greenhouse gas emissions.
“Previous studies of diet-related greenhouse gas emissions have focused mainly on the average diet in a given country,” said Diego Rose, the principal investigator on the project. “This study is the first in the United States to look instead at self-reported dietary choices of a nationally representative sample of thousands of Americans.”
The study was published in the journal Environmental Research Letters.
For the study, the researchers created a database that calculated the environmental impacts involved in producing more than 300 types of foods.
The database was then linked to the findings of a nationally representative one-day dietary recall survey of more than 16,000 U.S adults.
With both the database and survey, the researchers were able to rank different types of diets by their carbon footprint and the greenhouse gases they produced.
Diets that included a lot of beef or dairy had the highest impact and produced more greenhouse gases than the other diets.
In total, 20 percent of the diets with highest carbon footprint produced 46 percent of total diet-related greenhouse emissions.
“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,” said Martin Heller, the first author of the paper.
The results show the high levels of emissions from the meat and dairy industry, and the researchers recommend that people with high impact diets reduce the amount of meat they consume as an easy and sustainable solution for reducing emissions.