Greenhouse gases — water vapor, carbon dioxide, methane, ozone, nitrous oxide and chlorofluorocarbons — are causing the Earth to get warmer, thus leading to more natural disasters, health issues and food supply disruptions. To reduce humans’ carbon footprint (the average carbon footprint for a person in the United States is 16 tons per year, compared to the global average of 4), individuals and institutions can adopt a climate-friendly diet or a low-carbon diet, because what we eat matters.
“If each and every person in the United States gave up meat and dairy products on one or more days of the week, ideally, all days of the week, we would save the environment from thousands of tons of carbon emissions,” wrote Dana Hunnes for UCLA Sustainability. “Similarly, by reducing our animal-based foods consumption, we would reduce our water use at least by half as animal husbandry utilizes more than 50% of fresh water.” Hunnes pointed out that though 1 pound of tofu has half the protein beef does, it only costs 6 gallons of water per gram of protein versus 20 to 80 gallons of water per gram of protein for beef.
In 2018, Joseph Poore co-authored a study at the University of Oxford and discovered adopting a vegan diet would reduce a person’s carbon footprint by 73%. “A vegan diet is probably the single biggest way to reduce your impact on planet Earth, not just greenhouse gases, but global acidification, eutrophication, land use and water use,” he told the Independent. “It is far bigger than cutting down on your flights or buying an electric car. Avoiding consumption of animal products delivers far better environmental benefits than trying to purchase sustainable meat and dairy.”
Chloe Waterman, who works as program manager for Friends of the Earth’s climate-friendly food purchasing program, knows firsthand how effective small tweaks to our diets can affect the planet. “We have a bill that’s moving in the D.C. Council right now to reduce greenhouse gas emissions associated with the District of Columbia’s food procurement by 25% by 2030, which would be accomplished by shifting to more climate-friendly, plant-based menus and reducing food waste,” Waterman said.
So how do institutions and individuals eat a climatarian diet? Here’s what she advises.
Eat less red meat
Globally, the demand for meat has tripled in the past 50 years. According to a 2018 study on greenhouse gas emissions associated with U.S. diets, produce emits low amounts of greenhouse gases whereas beef emits the highest.
To raise cattle, land must be cleared, which removes what’s known as a carbon sink — an ocean, forest or any sort of vegetation that absorbs carbon from the atmosphere. Unlike pigs and poultry, cows require a lot of food and take a long time to grow.
“Sometimes I think people hold inaccurate views around the health benefits of meat, or lack thereof, from our perspective,” Waterman said. “Food is really emotional and deeply personal to people, which we understand. And that’s why most of our purchases are around expanding options and putting limits on meat. We’re not an organization that’s advocating for a fully vegan or plant-based diet.”
A recent Atlantic article stated: “Better all Americans cut meat consumption by 40% than 3% of Americans cut it out completely,” and a new Gallup survey discovered 23% of Americans have reduced their meat intake in the past year. Of those who said they’ve reduced meat intake, 49% said the environment was a major factor in the reduction. However, if consumers are going to eat meat, Waterman suggested buying grass-fed meat or pasture-raised chickens instead of factory-farmed meat.
Cut back on your dairy consumption
According to Waterman, cows emit high levels of methane, and the feed given to cows is produced with synthetic fertilizers, pesticides and water resources. A 2013 study found that “72% of the emissions occurred in processes prior to the milk leaving the farm.” Another factor in emissions is where the feed is grown. “Land that could otherwise be capturing greenhouse gas emissions is converted to grow feed instead, so there’s a big carbon opportunity cost as well,” she said.
Though the Environmental Protection Agency states that dairy cattle contributed fewer emissions than regular cattle (1.3% of the U.S. greenhouse gas total versus 3.4%), it’s still a significant amount. So if you opt out of drinking cow’s milk, what about the carbon footprint of plant-based milks?
Almonds and almond milk have a lower carbon footprint than cow’s milk, but almond milk has a higher water footprint. “For things like almond milk, if you’re really concerned about the climate, maybe that is something you want to drink in moderation,” Waterman said. “But it’s still less carbon intensive than cow’s milk is.” Look for other alternatives, like oat milk or pea milk, which are more climate-friendly.
All types of produce are a better choice for the environment than meat
While some produce is more planet-friendly than other types ― for example, the greenhouse gas chart lists potatoes as a lower-emission food than broccoli ― Waterman said it doesn’t matter too much which produce you eat.
“The differences between different types of produce are not quite negligible,” she said. “But when compared to the emissions associated with animal products, the differences are practically negligible. I would never advise somebody, if they want to eat a more climate-friendly diet, to eat an apple instead of an orange or an orange instead of a banana, because they’re all so low-emission relative to animal products.”
Sugar, for instance, has a low carbon footprint — just 0.45 to 0.63 kg of CO2 equivalent per kg, which would land between peanuts and tomatoes on the chart. But sugar has no nutritional value.
“We wouldn’t advise somebody to stop eating apples and eat sugar, or stop eating beef even and eat sugar instead,” Waterman said. “We’re looking for that balance in a diet that is high in fruits, vegetables, legumes, nuts and seeds — what all the healthy eating research points to as indicative of a healthy diet. And fortunately, that also happens to be the low-carbon diet. So if you’re eating a diet that’s high in those foods and low in meat, and especially low in red and processed meat, your diet is going to be bold and good for the planet and good for your health.”
Food miles aren’t as big a deal as you think they are — unless the food is air-freighted
Food miles are defined as “the distance food travels from where it is grown to where it is ultimately purchased or consumed by the end user.”
Waterman says a common misconception is that food miles are a big contributor to greenhouse gas emissions, “but that’s not true,” she said. “Food miles typically only account for 5-7% of the total emissions associated with a given food product.”
Buying local or from your farmers market can help cut down on how far your food has to travel, but how eco-friendly that food is still depends on how the farmers grow it.
“Having robust regional food systems will make us more resilient to the impact of climate change, but it’s not actually very helpful from a climate mitigation standpoint, unless you know that your farmer is using climate-friendly agriculture practices,” Waterman pointed out.
She suggests avoiding perishable foods that have been air-freighted. Although air freight makes up a small amount of transportation — via sea is number one — “transporting food by air emits around 50 times as much greenhouse gases as transporting the same amount by sea,” according to Our World in Data. It’s difficult to tell which foods get air-freighted, but keep in mind that asparagus, berries and green beans are a few foods that use air freight, and make sure you check the country of origin on labels.
Does eating a climate-friendly diet actually make a positive impact on the environment?
The research points to yes.
“Unless we shift our diets toward more climate-friendly foods and reduce food waste,” Waterman said, “even if other climate mitigation strategies are successful, we will still exceed the Paris Agreement target,” which has a goal to limit global warming to 1.5 degrees Celsius.
She continued: “So as long as this current global demand for meat and dairy continues to rise at the rate that it has been, that alone will screw us over when it comes to climate change. Intuitions — restaurants, schools, prisons, stadiums — should use that purchasing power and buy more climate-friendly food, and that absolutely can make a big difference when it comes to emissions.”