Environment. Penguin droppings effective... against global warming?

Penguins, iconic birds of the South Pole, help regulate the climate of Antarctica, an isolated territory particularly vulnerable to climate change, through... their excrement, a team of researchers has revealed.

According to their study published Thursday in the journal Communications Earth & Environment , the guano - a cocktail of urine and feces - of penguins, very rich in ammonia, contributes to the formation of fog and clouds above the white continent, thereby influencing temperatures.

An impact on the global climate

Previously little-known, this role is particularly important today, as Antarctica is rapidly warming due to climate change, threatening the survival of this species, the researchers point out. "The decline in penguin populations could lead to a positive counter-reaction to global warming," meaning it could contribute to rising temperatures, they write in the study.

"Most people might think, 'What does this have to do with me?' But actually, Antarctica's climate affects the global climate," says Matthew Boyer, an atmospheric scientist at Finland's University of Helsinki and co-author of the study.

Along with several colleagues, he traveled to the Marambio Antarctic base on Seymour Island to measure the concentration of ammonia in the air during the austral summer, when some 60,000 Adélie penguins gather some eight kilometers away to build their nests.

The need to protect penguins

They found that the ammonia content in the air increased significantly when the wind blew from the direction of the penguin colony, even after the birds had left to migrate. Their droppings continued to emit gas, loading the surrounding air with ammonia, the study notes.

Once in the air, ammonia interacts with sulfuric acid particles released by phytoplankton in the waters, forming aerosols that in turn contribute to cloud formation. “It’s a synergy between penguins and the oceans,” says Matthew Boyer, adding, “Sulfuric acid can form particles without ammonia, but when you have it, it happens 1,000 times faster.”

A clever mechanism that could prove extremely fragile at a time when the poles are warming faster than the rest of the planet, threatening both ocean ecosystems and the survival of certain species like penguins. "If the ocean's biological activity or penguin populations change, it will have an impact on this process," warns Matthew Boyer. He emphasizes the need to take the results of this study into account in biodiversity conservation strategies for this fragile and unique territory.