Updated June 8, 2025 at 6:02 AM PDT
Ten of thousands of penguins, clustered together on the Antarctic Peninsula, can produce some potent stenches. Now, scientists have found that all that waste could be powerful enough to cool the climate.
The gases from penguin poop help fuel cloud formation, scientists found, which can change the temperature in the Antarctic. Clouds act like giant reflectors, blocking sunlight that would otherwise be heating the planet.
Scientists from the University of Helsinki observed this at a colony of 60,000 Adélie penguins. As the wind shifted in the direction of the researchers, a fog formed over the course of a few hours. Using highly sensitive equipment, they measured high levels of ammonia gas, leading to cloud formation, which could be happening all over Antarctica. They published the findings in the journal Communications Earth & Environment.
The scientists say more research is needed to understand the overall effect on the climate, because while clouds reflect heat, they can also trap it under certain conditions. It's a key process to understand given the rapid changes at the farthest reaches of the world.
The poles are warming faster than the rest of the planet, as the climate gets hotter. That's altering the ecosystem for the penguins, as well as causing global impacts. Melting glaciers in Antarctica are causing sea levels to rise, posing a risk to millions of people around the world.
"It's quite interesting how such a small thing that you would never necessarily think about can have an impact on something else that's much bigger than itself," says Matthew Boyer, an atmospheric scientist at the University of Helsinki, who co-authored the study.
Gobs of guano
Penguins in Antarctica feast on fish and krill in the ocean and when they return to their nesting colonies, they leave behind the deposits of their digestive expeditions.
"It smells a bit like rotten fish mixed with pigeon poop," Boyer says. "They don't smell great."
Boyer and his colleagues analyzed the atmosphere and found ammonia gas around the penguin colony was 1,000 times higher than the normal background levels. In the air, that gas combines with other molecules.
"When they hit each other, they stick and these clusters of molecules end up growing," Boyer says. "It's kick-starting or boosting this process and actually forming particles at a much faster rate than it would otherwise."
Those particles become the seeds for clouds to form, because they attract water vapor. Clouds can only form when there are small particles around, like dust or pollution. And those clouds have a local impact.
"Clouds are important for climate because they're bright and they're white and they're in the sky," Boyer says. "They can disturb incoming solar radiation and they reflect it back out to space."
That effect is especially pronounced over the ocean, because without clouds, the dark surface of the ocean absorbs solar radiation and heats up. Boyer says more research is needed, though, because the effect of clouds can be mixed when they're over bright snow, since some can also trap heat at the surface.
Small poops, big impact
Other studies have found that seabirds in the Arctic could be producing a similar effect on the climate. Researchers measured and modeled the impact of bird guano there and found the clouds it produced have an overall cooling effect.
The reason something as lowly as bird poop can have an impact on the weather, the authors say, is that there aren't many other sources for cloud formation at the poles.
"There aren't a lot of existing particles in the Arctic," says Jeff Pierce, a professor of atmospheric science at Colorado State University, who worked on the Arctic study. "It's pretty clean. And small things, small details in these regions, such as the ammonia that comes off of poop, can make a difference in the number of particles."
While penguins may be helping slow the impacts of climate change, they're also affected by it. Changing ocean conditions can affect krill, their food supply.
"If you lose one penguin species, it will have a ripple effect through the entire Antarctic environment and this could have subsequent impacts that really affect the climate and the atmosphere in ways that we're just beginning to understand," Boyer says.
The challenge for scientists is understanding this process in a rapidly shifting world.
"It's changing in our lifespan as we study it," Pierce says.
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