Climate labels on menu items can help people choose between fish and beef

A new estimate of how bad can human warming get: Global food systems alone could be up to 2 degrees, according to a study by the Center for Climate Change (Centimetra)

Climate labeling on food products is rare and only a small amount of companies use positive labels that highlight low climate impacts. Legislation or regulation may be needed if warning labels are to be used on a large scale.

With an ever-expanding population—and a ballooning middle class consuming more meat—humanity is spewing ever-more planet-warming gasses in its quest to feed itself. A new estimate shows just how bad it could get: By the year 2100, the global food system alone could contribute almost a degree Celsius of warming. For context, humanity has already warmed the planet 1.1 degrees since the dawn of the Industrial Age. The Paris Agreement’s goal is to limit warming to 2 degrees above preindustrial levels, or ideally just 1.5 degrees. Food systems are just a small part of global emissions, and agricultural emissions alone could push us past 2 degrees.

To try and fill that gap, researchers conducted trials in which people were asked to imagine they were in a restaurant that served fast food, and pick an item from the menu that was vegetarian, vegan or plant-based.

Climate Change: What can we learn to protect ourselves from the future?” Comment on a recent study by Ivanovich and her co-authors

But, she added, these may not be the only effective design. “Other future research could be required to investigate different design options that may have a higher impact still using that positively framed label.”

Ivanovich and her colleagues arrived at the estimate by gathering previous data on the emissions associated with 94 food items, including fruits, vegetables, and animal products like meat and dairy. Producing these creates three key greenhouse gasses that the researchers considered. The machinery that transports crops to consumers emit carbon dioxide. Ruminants like cows and goats burp up methane—which is 80 times as potent a greenhouse gas—thanks to the fermenting plant material in their guts. Methane also comes from the practice of flooding fields to grow rice, which allows bacteria to proliferate and spew the gas as a byproduct. Synthetic fertilizers, which farmers use to give plants nitrogen they need to grow, comes from nitrous oxide, which is 300 times as potent.

Even worse, the authors of the new study, which was published today in the journal Nature Climate Change, caution that their calculation is likely an underestimate. Lead author Catherine Ivanovich, a climate scientist at Columbia University and Environmental Defense Fund, says that they are just considering how much additional warming could be expected if the global population ate exactly the same as it does today. “That’s not necessarily considering if that’s a realistic future, or if that’s really what the world is going to look like in 2100. But it gives us this very simple baseline that we can work off of.”