Can We Eat Our Way Out of Global Warming—and Get Healthier Too?
America’s steady diet of red meat and junk food, and its rising popularity around the world, isn’t just killing off people—it’s strangling the planet.
That’s the message at the heart of a study published this week in the journal Nature, in which researchers from the University of Minnesota examined the impact of global diet trends on public health in relation to their impact on climate change.
While the notion “what’s good for you is good for the planet” has long fueled any number of environmental campaigns (not to mention Madison Avenue’s efforts to hawk everything from laundry detergent to face soap), there previously had been little effort put into scientifically establishing the link.
Indeed, as the study’s lead author, G. David Tilman, a professor of ecology at the University of Minnesota, tells Civil Eats, “This is the first time this data has been put together to show these links are real and strong and not just the mutterings of food lovers and environmental advocates.”
That may not be 100 percent true—see, for example, the Environmental Working Group’s Meat Eater’s Guide to Climate Change + Health from 2011—but Tilman’s analysis nevertheless reinforces how insane it is for the world to keep adopting America’s penchant for burgers and fries.
Even as President Obama and Chinese President Xi Jinping made global headlines this week by vowing to curb or limit their countries’ respective greenhouse gas emissions, Tilman shines a spotlight on what has long been ignored by the greater public as a significant source of climate change–causing pollution: agriculture. In the U.S., farming accounts for 10 percent of total greenhouse gas emissions, but some of those pollutants are a real doozy, such as the methane emitted by cattle (which is 20 times more potent a greenhouse gas than carbon dioxide) and the nitrous oxide that’s generated when chemical fertilizer is applied to soil (some 300 times more potent).
If current trends continue, with rising affluence around the world leading to more people adopting an American-style diet, Tilman estimates that by 2050 we could see an 80 percent increase in annual greenhouse gas emissions related to food production, from 2.27 gigatons to 4.1 gigatons.
The reasons for this are legion, including more land cleared to raise the copious amounts of sugar that fuel the American processed-foods industry. But when you’re talking about agriculture and climate change, much of the discussion invariably centers on meat—in particular, beef.
As the Environmental Working Group has charted, bringing a single kilogram of beef to your dinner table generates 27 kilograms of global warming pollution. Compare that with, say, just 1–3 kilograms for an equivalent amount of food such as beans, nuts, and vegetables.
Thus, it comes as little surprise when Tilman concludes that if, instead of embracing the global proliferation of American burger joints and the like, humanity veered to a more plant-based diet, the global warming pollution associated with food production would essentially flatline in the coming decades, even accounting for the rise in human population.
We’d all be much healthier too. Tilman finds that a vegetarian diet reduces the incidence of type 2 diabetes by 41 percent; a diet that includes fish yields a 25 percent decline; and the so-called Mediterranean diet (lots of fruits and vegetables and seafood, with some meat) is associated with a 16 percent drop.
Likewise, these diets have been linked to a reduction in your risk for death from heart disease by 20–26 percent, and a 7–13 percent reduction in cancer risk.
While this is not news to anyone inclined to click on the latest diet-related headlines, that Tilman is explicitly linking diet with health and climate change is big news—in the sense that it gives us the sort of bigger picture we all should be considering, even as we answer the humdrum question of what we’re going to have for dinner tonight.