Toward the Forest

Estimating the Impact of Diet on the Planet

Most of us who think about food systems have a vague sense that our diet has a meaningful impact on the health of the planet. Beef is typically thought to be a bad actor. Eating more plant based foods should help. But an ambitious new study in Nature Sustainability aims to assign specific numbers to the effect of almost everything we eat on the health of our environment. It offers a few surprises.

Lead author Ben Halpern explains his motivation for doing this work:

“I became a pescatarian years ago because of wanting to reduce the environmental footprint of what I eat. But then I thought, I’m a scientist, I should really use science to inform my decisions about what I eat. That’s actually why I started this research project. And now that we have the results, I see that from an environmental perspective, chicken is actually better than some seafood. And so I’ve shifted my diet to start including chicken again, while eliminating some high-pressure seafoods like bottom-trawl caught cod and haddock. I am actually eating my words.”

Concentrated Effects

What this study identifies is a substantial concentration of effects. Just five countries account for almost half of the environmental footprint of land-based food production. Author Melanie Frazier says:

“Cumulative pressures of food production are more concentrated than previously believed, with the vast majority – 92% of pressures from land-based food production – concentrated on just 10% of the Earth’s surface.”

Aquatic systems for food production have their problems, too. They produce only one percent of the food we eat, but they account for ten percent of the pressure our diet puts on the planet.

Prioritizing the Health of the Planet

In making choices about our diets and food systems, we see a lot of preoccupation with direct human health effects. Inflated claims for the effects of plant-based foods on personal health often seem fanciful. But that’s no reason to discount the environmental effects of our food systems.

In fact, the health of the planet deserves priority by itself as we reform our global food systems. Without a healthy planet, human health isn’t possible. So we don’t need bogus health claims to justify making better choices for the planet.

Click here for the new study in Nature Sustainability, here and here for further perspective.

Toward the Forest, woodcut by Edvard Munch / WikiArt

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October 27, 2022