Things aren’t looking good for Planet Earth.
“If you look at average temperatures around the world going back to 1850, what’s most worrisome is the acceleration in climate change,” says Walter Willett, professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health.
The last five years were the hottest years in centuries, according to the National Oceanic and Atmospheric Administration.
“If we have just two degrees Celsius warming globally by 2100, that will have disastrous effects on many earth systems,” warns Willett.
“Yet we’re now on track to go well beyond two degrees.”
One reason the planet is heating up more quickly
“Increases in temperature lead to vicious circles,” explains Willett.
For example, as temperatures rise, they start to thaw the permafrost—ground (mostly near the North and South Poles) that remains frozen year round—and microbes begin decomposing the plant matter in the soil.
“That releases more methane and carbon dioxide, which further increases global temperatures,” says Willett.
By 2050, sea levels are expected to rise by 4 to 8 inches on the West Coast, 10 to 14 inches on the East Coast, and 14 to 18 inches on the Gulf Coast, causing even “moderate” flooding ten times more often than today. And drought is gripping much of the West.
The bottom line: “The climate is starting to spin out of control,” says Willett, “and is probably already reaching some irreversible changes.”
The EAT-Lancet flexitarian diet
Willett co-chaired the EAT-Lancet Commission, which assembled 37 leading scientists from 16 countries with expertise in human health, agriculture, planetary sciences, political science, and other disciplines.
“Our challenge was to answer the question: How can we feed the 10 billion people who will inhabit our planet by 2050 with a diet that is both healthy and sustainable,” he notes. “This was a huge challenge from the nutrition side.”
Yet the commission’s 2019 report managed to come up with a realistic diet that’s not too different from a traditional Mediterranean diet.
“You can boil it down to a plate that’s about half fruits and vegetables, with no more than one serving of dairy per day and no more than one other serving of animal food per day,” explains Willett.
But that doesn’t mean a daily burger. “Red meat—beef, pork, and lamb—would be quite low, at no more than one serving a week,” says Willett. “Seafood, eggs, and poultry could each go to two servings a week.”
Other protein would come from plants like beans, soy foods, and nuts. “And the range for animal proteins includes zero, so one could be a vegan and still have a very healthy diet,” adds Willett.
“The diet would also emphasize whole—not refined—grains and unsaturated plant oils and would keep sugar intake quite low.”
Going flexitarian
The EAT-Lancet flexitarian (flexible vegetarian) diet allows 1 serving of dairy + 1 other serving of animal food per day.
- Start with plants. Vegetables, fruit, beans, nuts, soy foods, and whole grains are your base.
- Add optional dairy. You can add one serving—1 cup of milk, 1 oz. of cheese, or 5 oz. of yogurt—per day.
- Add optional seafood, poultry, or eggs. You can add one small serving—3½ oz. raw (about 3 oz. cooked) or 1 egg—per day.
- Limit red meat to 3 oz. (cooked) per week. You can have, say, one burger a week or one 12 oz. steak once a month.
Food is just part of the planet’s problem
“It’s critical to get to virtually zero fossil fuel consumption by 2050 if we’re going to stay under two degrees Celsius of warming,” says Willett.
“But if we stay on our present business-as-usual model for food, we won’t be able to stay within planetary boundaries even if we do get to zero fossil fuel by 2050.”
That’s because by then, the planet will have another 2 billion people, and worldwide, diets are shifting to more meat and dairy.
“But if we adopt the EAT-Lancet targets and cut fossil fuels, we could squeak by and feed 10 billion people a healthy and sustainable diet,” says Willett.
“That won’t be easy, but it could allow us to pass on to our children a viable planet.”