Penguin guano turns Antarctic snow green and speeds its melt

A study making headlines on 10 October 2026, published in the Journal of Geophysical Research: Biogeosciences and led by Alia Khan of the University of Colorado Boulder, finds that penguin colonies along the Antarctic Peninsula are inadvertently supercharging patches of green snow algae with their nutrient-rich droppings. As penguins waddle between nests and the sea they spread phosphate-laden guano across the snow, feeding dense blooms of microscopic algae. Field measurements show these green patches absorb roughly 40 per cent more solar energy than clean, white snow, melting faster and expanding snow- and ice-free ground around rookeries. The research team mapped bloom extent along the peninsula using drones and satellite imagery and found the green areas are growing as regional temperatures rise and penguin colonies shift southward. Crucially, current projections of Antarctic ice loss do not yet account for this biological feedback, meaning estimates of future snow and ice retreat on the peninsula may be too low. The story was picked up by phys.org, Nautilus and major science news aggregators, and resonated as a vivid, visual example of how biology and physics are tangled up in climate change.