It has been proposed that changes in diet can help reduce greenhouse gas emissions from the food supply chain. However, not much research has been made on the feasibility and affordability of low-carbon food choices among the U.S. population and how these choices can possibly impact diet and climate change.
According to a new study that offers the latest and most detailed estimate of greenhouse gas emissions produced by U.S. consumer food purchases, Americans can help cut down greenhouse gas emissions if they stay clear of animal proteins, including meat, and instead purchase other food products.
“We found that households that spend more of their weekly food budget on beef, chicken, pork and other meats are generating more greenhouse gas emissions. Our study shows that encouraging consumers to make food choices that are lower in greenhouse gas emissions can make a real difference addressing climate change,” stated Rebecca Boehm, lead author of the study and a University of Connecticut Postdoctoral Fellow with the Rudd Center for Food Policy and Obesity and the Zwick Center for Food and Resource Policy, who started this work at the Friedman School of Nutrition Science and Policy at Tufts University.
Changes in food consumption could be one way to reduce greenhouse gas emissions because according to the study, food purchases were responsible for 16% of U.S. greenhouse gas emissions in 2013. In contrast, industrial activity accounted for 21% and residential and commercial activity accounted for 12% of the country’s greenhouse gas emissions.
The study was performed by scientists along with the Zwick Center and the UConn Rudd Center, the Friedman School of Nutrition Science and Policy at Tufts University, the U.S. Department of Agriculture’s Economic Research Service, and the University of Missouri. The study has been reported in the journal Food Policy.
Using nationally representative data on food purchases, the researchers linked comprehensive household purchase data to a U.S. Environmental Protection Agency tool, which can be used for calculating greenhouse gas emissions from each stage of the food supply chain, such as production, manufacturing, transportation, distribution, and restaurants and retail stores.
“This study is a major advancement in our understanding the contribution of U.S. food choices to climate change,” said Boehm.
Although many studies were performed in the U.S. before, they did not invariably capture the amount of greenhouse gas emitted from all areas of the food system.
The study provided the following findings:
- Industries producing pork, beef, and other red meat products account for approximately 21%—the largest share of greenhouse gas emissions from household purchases, while fresh vegetables and melons; cheese industries; and butter and milk products account for 11%, 10%, and 7%, respectively.
- Household food spending contributes to greenhouse gas emissions, which differed by educational attainment and race. Over 80% of households that generated very high greenhouse gas emissions from their food purchases (top fifth of households) were white.
- Compared to about 12% of households in the bottom fifth for greenhouse gas emissions, 26% of households with the highest (top fifth) level of greenhouse gas emissions included a survey respondent with a college degree.
- Less greenhouse gas emissions from food purchases (when not considering other household characteristics) were observed from participation in the federal Supplemental Nutrition Assistance Program (SNAP).
- Only 9% of households in the top fifth for greenhouse gas emissions took part in SNAP, and about 24% of households in the bottom fifth for greenhouse gas emissions took part in SNAP.
“It’s striking that many of the opportunities for environmentally-friendly dietary changes are with the households that have the most resources,” said senior author Sean B. Cash, Ph.D. Cash is the Bergstrom Foundation Professor in Global Nutrition at the Friedman School of Nutrition Science and Policy at Tufts. “Changes in food consumption in these households could reduce greenhouse gases by a disproportionate amount.”
For the first time, our study shows the association between the greenhouse gas emissions generated by the food system, household food spending patterns, and sociodemographic characteristics. These findings can inform the debate on which diets and food spending patterns can best mitigate greenhouse gas emissions from the food system, while informing educational efforts to encourage low-carbon diets among the U.S. population.
Rebecca Boehm, Lead Author
Co-authors of the study include Parke Wilde of the Friedman School of Nutrition Science and Policy at Tufts University, Christine Costello of the University of Missouri, and Shelly Ver Ploeg of the USDA Economic Research Service.
The Zwick Center, the Tufts University Institute of the Environment, and the Friedman Family Foundation Doctoral Fellowship supported the work.