|December 12, 2017|
The diet that helps fight climate change
|Ben Houlton spends a lot of time thinking about what's on your dinner plate.|
"If you take a steak and ask the question, 'What's been put into making that appear on my plate?', you can trace it back all the way to the fertilizer that's used to grow the food and then the grains which are used to feed the animals," said Houlton.
As director of the John Muir Institute of the Environment at the University of California, Davis, Houlton studies how food production affects the environment and creates greenhouse gases. Nearly every step that goes into food production has some impact on global warming, and it adds up: Agriculture and land use is responsible for nearly a quarter of all global greenhouse gas emissions.
A lot of people count calories, or try to cut carbs from their diet --- the next step could be cutting carbon from your diet. Take that steak on your plate: Eating an average-sized steak for dinner has a comparable carbon footprint to driving about three miles in a standard gas-powered car. Get a large steak with some sides, and you easily double the impact.
"We have to think about the methane that's being released from animals and rice paddies and areas where we're growing food. And we have to consider the nitrous oxide gas that's being produced from the fertilizers we're feeding to the microbes that live in the soil. And you add all of that together, and you get a better understanding of global climate impacts of our food system," said Houlton.
Houlton's work on nitrogen modeling and the often-overlooked climate effects of fertilizers has helped improve global comprehension of just how much our food system impacts global warming, and lets lawmakers craft more targeted and effective agricultural policies.
His research has also crystallized for him that we can't just wait for better policies and futuristic technology to swoop in and save the day: This is one area where we have the power as individuals to make a significant impact on climate change right now.
"It's very easy to get depressed, to feel sad about all the changes that are happening and feel like you can't contribute to the solution," said Houlton. "Well, here is a shovel-ready opportunity."
The power of choice
Maya Almaraz, a postdoctoral researcher who works with Houlton at UC Davis, said she wishes she had a magic wand that could make everyone understand just how powerful their food choices can be.
"A lot of people feel really helpless when it comes to climate change, like they can't make a difference," said Almaraz. "What our research is showing is that your personal decisions really can have a big impact."
Different foods have vastly different carbon footprints. Swap your steak for fish, for example, and you get an eight-fold reduction in emissions. And if you're game to switch that to beans or lentils your emissions drop to near zero. It really gets interesting when lots of us start making similar changes.
"What we're finding is that reducing your meat intake can actually offset the emissions from all of our cars and even double that," said Almaraz. "It's not really something that you write into the Paris climate agreement. It's something we have to decide on every day."
Eating our way out of climate change
But to make a dent in something on the scale of global warming, where time isn't on our side, are drastic measures required? Do we all have to give up that steak --- or (shudder) bacon --- and switch to a vegan diet to save the planet?
While only around six percent of the U.S. identifies as vegan, according to one recent survey, Americans are starting to embrace some vegetarian habits: Per capita beef consumption has been declining since the 1970s, dropping off steeply in the last decade according to USDA data, and the meat alternatives industry is growing rapidly. Even so, the U.S. still has one of the highest per capita meat consumption rates in the world, and meat is deeply ingrained in American culture --- in short, we're not all going vegan anytime soon.
"We're not saying you should go cold turkey --- although eating turkey alone might be a good option, better than eating red meat," said Houlton. "What we are saying is consider moderating the amount. Maybe, instead of having meat two times a day, have it once a day. If each of us take baby steps, we'll find that we can go a mile pretty quickly."
While Houlton's climate models find that a vegan diet reduces your carbon footprint more than any other dietary choice, a Mediterranean diet is really close.
"Our studies are showing that the Mediterranean diet --- which is rich in nuts and beans and has a lot of fish, maybe chicken once a week, maybe red meat only once a month --- if everyone were to move toward it, it's the equivalent of taking about a billion or more cars of pollution out of the planet every year," said Houlton.
To put that in perspective, Houlton's models show that global adoption of a Mediterranean diet could help reduce global warming by up to 15 percent by 2050.
The Mediterranean diet has additional benefits. Previous studies have found that a Mediterranean diet can reduce the incidence of Type 2 diabetes, heart disease and other chronic diseases. Multiple studies have linked the Mediterranean diet to increased overall longevity.
The takeaway, according to Almaraz, is that the focus should be on reduction.
"Eliminating 90 percent of your meat intake is more important than eliminating all of your meat intake," said Almaraz.
Houlton's advice is to feel empowered: consumer choice can change trends almost overnight. He also thinks you should feel selfish, but in a good way.
"Put your health first. Be really selfish about your health. Make healthy choices in terms of the food you're putting into your body and watch the planet repair itself at the same time."