If you have ever stood in front of a penguin enclosure at an aquarium–or better yet traveled to Antarctica, New Zealand, or parts of southern Africa to see them in the wild–one reality really sticks out about these flightless birds. The smell. Their guano (aka poop) is pungent and plentiful, and dark stains of guano sticking out on white ice have even helped scientists find previously unknown penguin colonies.
The ammonia released from their poop also might help reduce some of the devastating effects of climate change. This gas helps influence cloud formation, which can cool down surface temperatures. The findings are detailed in a study published May 22 in the journal Nature Communications Earth & Environment.

Why ammonia?
Antarctic ecosystems are under serious threat due to human-driven climate change, with some penguin colonies failing to breed altogether. Warmer temperatures means less critical sea ice for penguins, sea birds, seals, and whales. Penguins are a key species in this ecosystem at the bottom of the world and also are major emitters of ammonia in the region.Â
Ammonia is an atmospheric gas that can increase cloud formation by reacting with gases containing sulphur. In turn, this increases the creation of aerosols–the particles that give water vapour a surface to condense upon. All of that condensation leads to cloud formation.
“Aerosol particles are necessary for cloud formation; liquid water will not condense to form cloud droplets without the presence of aerosol particles,” Matthew Boyer, a study co-author and atmospheric scientist at the University of Helsinki in Finland, tells Popular Science. “Clouds influence the surface radiation budget, which affects surface temperature. Therefore, clouds impact climate change. This is true across the entire planet, not just in Antarctica.”Â

Since higher concentrations of aerosol particles creates clouds that are more reflective of the sun’s rays, the strength of an area’s aerosol particle sources matters.
“In general, the Antarctic atmosphere is a pristine environment,” says Boyer. “It’s located far away from human pollution sources, and the background aerosol particle concentrations are low as a result. New particle formation, occurring from gases emitted from natural sources (e.g., penguins and the ocean), is therefore an important source of aerosol particles in the region.”
The resulting clouds can act as insulating layers in the atmosphere and those layers often help lower surface temperatures and can affect the amount of sea ice coverage. However, the specific interaction between penguins and their ammonia filled poop and the Antarctic climate is not well understood.
[ Related: A small amount of penguin poop is enough to spook krill. ]
Standing downwind
In this new study, Boyer and his colleagues measured the concentration of ammonia in the air at a site located near Marambio Base, Antarctica between January 10 and March 20, 2023. When the wind blew from the direction of a colony of 60,000-individual Adélie penguins (Pygoscelis adeliae) about five miles away, the ammonia concentration increased to as high as 13.5 parts per billion. That figure is over 1,000 times higher than the baseline value that is naturally found in Antarctica (less than 10.5 parts per trillion). The ammonia enhanced the particle concentrations in the clouds up to 30 times than the background, according to Boyer.
Around the end of February, the penguins migrated from the area. The ammonia concentration was still more than 100 times higher than the baseline, because the penguin guano left at the colony site still emitted the gas.Â
“The most surprising part for me was the strength of ammonia emissions from the penguin guano for a month after the penguins were no longer present at the colony,” says Boyer. “They left for their annual migration, but the guano they left behind in the soils continued to emit gas ammonia at ~100 times higher than the baseline.”

This indicates that the cloud-building ammonia emissions from penguins may cover even more of coastal Antarctica.
To confirm that the increase in ammonia concentration eventually affected the cloud formation, the team recorded several additional atmospheric measurements during a single day. When the wind blew from the penguin colony, the number and size of the aerosol particles recorded at the site sharply increased. Approximately three hours after the wind changed, the team saw a period of fog. The team believes that this fog was likely a result of that increased aerosol particle concentration and cloud formation.Â
According to the team, the data suggests that penguin poop may be helping reduce some of climate change’s effects on an ever-warming Antarctica.Â
“Our measurements demonstrate that these environmental and ecosystem changes will subsequently impact the atmosphere and the climate of the region,” says Boyer. “This matters, because changes to the climate/ecosystem in Antarctica can have consequences for global climate.”