It may be time to order a veggie burger instead of a rack of ribs. For years, climate scientists have suggested eating less meat to cut down on greenhouse gas emissions, but the researchers behind a new study say dietary changes are essential to prevent global catastrophe.

The study—published in the journal Nature—is the most comprehensive analysis of how the global food system affects the environment, The Guardian reports. In addition to greenhouse gases being released by livestock, deforestation and water shortages are a couple of other ways that current food production methods hurt the planet. Researchers say there is no easy fix to slow climate change, but reducing our intake of meat is one way that everyone can help out.

“There is no magic bullet,” Marco Springmann, who led the study, tells The Guardian. “But dietary and technological change [on farms] are the two essential things, and hopefully they can be complemented by reduction in food loss and waste."

That doesn’t mean you have to become a vegetarian or vegan, though. Researchers recommend a “flexitarian” diet, which involves occasionally eating meat. For this to make a positive impact, the average global citizen would have to eat 90 percent less pork, 75 percent less beef, and half the number of eggs they normally consume. If you simply can't give up steak, the Climate, Land, Ambition & Rights Alliance (CLARA) recommends consuming just two 5-ounce servings of meat per week. Researchers in the Nature study say beans, nuts, and seeds are all recommended sources of protein.

By their estimates, a global shift towards a flexitarian diet would cut greenhouse gas emissions by 56 percent, and would reduce other environmental impacts by 6 to 22 percent. They say the global food system emitted around 5.7 billion tons of carbon dioxide in greenhouse gas emissions in 2010, in addition to using vast amounts of cropland, fresh water, and fertilizers containing nitrogen and phosphorus (which pollute waterways as agricultural runoff).

“If socioeconomic changes towards Western consumption patterns continue, the environmental pressures of the food system are likely to intensify, and humanity might soon approach the planetary boundaries for global freshwater use, change in land use, and ocean acidification,” researchers write in their paper. In other words, the current food system might not be able to sustain the projected population of 10 billion people in 2060.

The study follows the recent release of a UN report in which scientists warned that we have only 12 years to limit global warming to 1.5 degrees Celsius. Failing to do so would result in more extreme weather events, including drought, floods, and severe heat. If you're looking for other ways to reduce your carbon footprint, try flying less, biking more, and turning down your thermostat. Every bit helps.

[h/t The Guardian]