Overview

• Fieldwork at Marambio Base from January to March 2023 informed a Communications Earth & Environment paper published in May 2025.
• Ammonia concentrations downwind of a 60,000-strong Adélie colony peaked at 13.5 parts per billion, or roughly 1,000 times baseline levels.
• Chemical reactions between guano-derived ammonia and sulfur-containing gases accelerated cloud condensation nuclei formation by about 10,000 times.
• Clouds seeded over open ocean are projected to cool surface temperatures, whereas clouds over ice might trap infrared radiation, leaving net climate effects uncertain.
• Accelerating declines in penguin populations threaten to weaken this guano-driven cooling feedback in a warming Antarctic environment.