It varies from person to person. But a number of studies have concluded that people who currently eat a meat-heavy diet — including much of the population of the United States and Europe — could shrink their food-related footprint by one-third or more by moving to a vegetarian diet. Giving up dairy would reduce those emissions even further.

If you don’t want to go that far, there are still ways to shrink your individual footprint. Just eating less meat and dairy, and more plants, can reduce emissions. Cutting back on red meat in particular can make a surprisingly large difference: According to a World Resources Institute analysis, if the average American replaced a third of the beef he or she eats with pork, poultry or legumes, his or her food-related emissions would still fall by around 13 percent.

Keep in mind that food consumption is often only a small fraction of a person’s total carbon footprint: There’s also driving, flying and home energy use to consider. But dietary changes are often one of the quickest ways for many people to lighten their impact on the planet.