The environmental case for eating vegetarian, in one sentence

California’s devastating drought is focusing attention on the water footprint of various foods — particularly delicious, delicious almonds, which require about a gallon of water each.

But as various analyses show, red meat is far worse than even almonds on this score. It takes almost twice as much water to produce a calorie of beef as it does to create a calorie of almonds. Any discussion of how to eat to best preserve water needs to begin with this sentence:

the water footprint (WF) of any animal product is larger than the WF of a crop alternative with equivalent nutritional value.

That’s from an analysis water expert Arjen Y. Hoekstra published in the journal Environmental Research Letters. He goes on to explain that the average water footprint per calorie of beef is 20 times larger than for cereals and starchy roots. In fact, 40 percent of the world’s cereals are grown to feed animals being raised for food.

Almonds are getting a lot of attention because California is in drought and California produces a ton of almonds. But in terms of global water supply — which is a much bigger deal than California’s water supply — almonds just don’t matter that much, and for the obvious reason: people don’t eat many almonds, so the world doesn’t produce that many almonds.

It’s grains, meats, and starches that dominate global diets and thus global water use. You can see this in a paper Hoekstra co-authored on water footprints. Together, cereals and meat account for 49 percent of global water consumption. Nut production is so small that it’s tucked away under “other.”

Of course, water isn’t the only resource we should worry about agriculture using. Fossil fuels are another — and, given their contribution to global warming, perhaps a more pressing one. But the story here is much the same. “An average of 25 kcal of fossil energy is required to produce 1 kcal of animal protein, which is ten times greater than in the case of plant protein,” writes Hoekstra.

I’ve always found it a bit perverse that SUVs get so much of the blame for global warming and steakhouses get so little. In terms of global emissions, meat consumption is a much bigger deal than Land Rovers — indeed, a UN report found agriculture is a bigger contributor to global warming than transportation.

And that’s good news, in a way. It’s much easier for someone to choose to eat a bowl of spaghetti for dinner, or to go meatless on Mondays and Wednesdays, than to change their car or find a job that doesn’t require a long commute. Yet the environmental movement is comfortable shaming people for their driving choices in a way it would never shame them for their food choices.

But to bring this back to water, almonds are beginning to play the role of SUVs in the discussion over California’s drought. The amount of water they require is striking, and they themselves are a bit of an indulgence, but they’re far from the biggest problem — for California or for the world.

Personal note: Since I think it’s relevant to this post, I’m not a full vegetarian, and I’m not telling anyone else to be, either. I think both the ethical and environmental case for vegetarianism is strong, and I stick to a vegetarian diet when I’m at home. (I eat meat when I travel, because I am a weak, fallible person.)

But a key point here is that in terms of greenhouse gas emissions and water use, you can make a huge difference by eating less meat, even if you don’t go full vegetarian. If everyone in developed countries cut their meat consumption by half, that would be a much bigger deal than if 5 percent of the population went entirely vegetarian. So don’t let the fact that you don’t want to go all the way keep you from going some of the way.