Penguin poop, also known as guano, is notoriously smelly. But the ammonia in the birds’ excrement does more than just stink—it can play a role in cloud formation over Antarctica. Those clouds affect climate systems,

New research shows that penguin guano in Antarctica is an important source of ammonia aerosol particles that help drive the formation and persistence of low clouds, which cool the climate by reflecting some incoming sunlight back to space.

Antarctica's icy wilderness is warming rapidly under the weight of human-driven climate change, yet a new study points to an unlikely ally in the fight to keep the continent cool: penguin poo.