Welcome to Burning Questions, a series where Earther answers the most common asks we get on how to address climate change. Many people want to do something, anything to help address the climate crisis. We answer your questions about how to help change your life—and the systems that will save us. Check out our past Burning Questions here.
The effects of animal agriculture on the planet are... not great! Globally, the livestock industry is responsible for nearly 15% of greenhouse gas pollution. In the U.S., cows alone account for 27% of methane emissions.
Chicken and pork are also environmental nightmares. Though each industry emits less greenhouse gas pollution than beef, both require the production of a shitload of soy (more than a third of the world’s soy is fed to poultry and roughly a fifth goes to pigs), which drives deforestation in places like the Amazon.
The climate and ecological damage from animal agriculture has some folks turning to veganism. But what about seafood? If you’re not ready to give up meat entirely, is it OK (or at least better) to eat salmon? What about shrimp? We know hot girls love sardines, but does eating them make the planet hotter? The answers are complicated.
From a strictly emissions point of view seafood is generally a better choice than other kinds of meat.
“Seafood has a smaller carbon footprint than other animal proteins, on average, because fishing doesn’t require farmland or care of livestock,” Anna Baxter, communications specialist at ocean conservation organization Oceana, said in an email, citing a 2012 study.
There are even some ground rules you can follow to ensure your fish dinner has the lightest footprint possible. Wild-caught is usually better. Smaller species like anchovies, herring, and sardines are usually the best options because they’re lower on the food chain and they’re less often overexploited. Mollusks like oysters, mussels, and scallops tend to be relatively climate-friendly options because they can filter sustenance from the water instead of requiring feed. There are guides out there, like the Monterey Bay Aquarium Seafood Watch, that can help make more informed choices.
But still, things can get complicated.
“Unlike cattle, fish aren’t ruminants that produce methane when they burp and fart,” said Jan Dutkiewicz, a postdoctoral fellow at Concordia University and visiting fellow in the Animal Law and Policy Program at Harvard University. “And unlike, say, chicken, they’re not produced in polluting environments like [concentrated animal feeding operations] that are highly emitting. ... But there are other issues.”
Farming fish has a higher climate impact than catching wild seafood. In 2017, the fish farming sector generated half a percent of human-caused greenhouse gas emissions, putting it roughly on par with the emissions of the Netherlands.
While many kinds of wild-caught seafood are more climate-conscious choices, that’s not the case for all of them. Crustaceans like shrimp and lobster are associated with some of the highest carbon emissions because the trawling boats used to catch them and reel them in have to constantly stop and start to set and collect traps, using a lot of fuel in the process. A 2018 study in the journal Nature Climate Change found that lobster and shrimp fisheries can produce more emissions than chicken and pork farms. Another report, released this year, found that bottom trawlers release a gigaton of carbon dioxide every year, which is as much as the entire aviation industry.
There are also a wealth of impacts not tied to climate change. Bottom trawling can wreck delicate seafloor ecosystems while fishing gear is a major source of plastic pollution in the ocean. That poses a major risk to all types of marine species, including apex predators like sharks. Overfishing is also a major concern, with the United Nations warning that a third of the world’s fisheries are being used at unsustainable rates. Fish farms are also sources of pollution and disease that can affect wild species.
Swapping out a hamburger for a salmon burger is one step to reduce your diet’s carbon footprint. But it can’t be the only step.
An April report found that U.S. fishery managers are failing in their duty to prevent overfishing and enforce annual catch limits. Pushing lawmakers for more oversight to ensure laws are being enforced would be a major systemic action. But policies can also be improved, particularly as climate change puts more pressure on fisheries. A bill introduced this summer would improve existing policy to protect more creatures and better account for climate change.
Fishing is also a global trade. Last year, the World Trade Organization failed to reach a deal on how to cut subsidies to unsustainable fish farms that have helped destroy the world’s fish stocks. Joining groups fighting for a strong agreement next year is another avenue to start to further tip the scales.
Frances Withrow, a marine scientist at Oceana, wrote in an email that the group is also campaigning to freeze bottom trawling and ensure fishing gear is more sustainable to cut down on bycatch. It’s yet another avenue into ensuring others choosing to eat seafood have better options.
By and large, though, the science shows that the most sustainable protein options aren’t animal-based at all; they’re plant-based proteins like beans and lentils. So another way to shrink seafood’s environmental impact is to shrink the whole sector by expanding more sustainable alternatives. Governments spend tens of billions worldwide annually on the fishing economy, and those incentives can encourage overfishing and overexploitation.
“There’s a very strong case to be made that if people who farmed fresh, healthy vegetables, beans, and pulses were given that same sort of support instead ... to develop better varietals, new varietals or just to produce at higher scale, we could achieve lower costs and incentivize people to eat those,” said Dutkiewicz.