A monumental new study demonstrates that one-fifth of the American population is responsible for nearly half of all food-based emissions. Popsci reports that people who eat a lot of animal protein, especially beef, account for a larger share of greenhouse gas emissions — although, author Sara Chodosh also illustrates the extreme complexity behind the study’s potentially groundbreaking conclusions. Read on for a closer look.

tomato, vegetables, fruit, agriculture, growing tomato, tomato harvest

Published in Environmental Research Letters specifically sought to understand how diet and associated emissions varies among the American population. Martin Heller, an engineer at the University of Michigan’s Center for Sustainable Systems and study contributor, told Popsci it was surprising to realize just how varied they are.

“I don’t think any of us really had a strong sense of how distributed the greenhouse gas emissions would be,” he says. “That was perhaps the most striking result.”

Getting to the meat of the matter (sorry, I couldn’t resist) involved consulting several different databases and picking apart the life-cycle analysis of every morsel.

Chodosh writes: “The NHANES survey results can tell you what a broad spectrum of American plates look like on any given day, but tells you nothing about the environmental impact of those foods. To do that, you have to go to the Food Commodities Intake Database, run by the EPA, and figure out how much meat might be in that meat lasagna, or how many tomatoes are in a generic salad. From there, you have to link the quantities of each type of food to the emissions associated with producing it.”

Related: Garlic may be the key to slashing methane emissions from cows

When evaluating the emissions of a single tomato, it was necessary to know how much fertilizer was used in its production, and then how much fuel was used to transport that tomato. With poultry, the researchers had to also consider feed production, and when analyzing the greenhouse gas emissions associated with eating beef, they had to calculate the amount of methane released by cow burps. I urge you to head over to Popsci to read the full details, because this short synthesis doesn’t do their reporting justice, but here’s the bottom line that we found so interesting:

What next? Now that we know one-fifth of the American population is producing nearly half of food-based emissions — which in their turn are helping to melt glaciers and unleash devastating wildfires, not to mention the numerous adverse health hazards attributed to climate change — what do we do with that information?

Heller tells Popsci, “Clearly we’ve not been very good at encouraging people to shift their diets for their own health. Relative to what our recommended healthy diet is, Americans do pretty poorly,” he says, “But I’ve started to try to think about it as the secondhand smoke of diet choice.”

Fascinating. If you understood that your dietary choices directly hurt your neighbor, would you make a switch?

+ Environmental Research Letters

Via Popsci

Images via DepositPhotos 1,2