The global authority on threatened wildlife has declared the emperor penguin an endangered species. Climate change is the mechanism: as Antarctic sea ice shrinks, the stable platforms emperor penguins need for breeding and raising chicks disappear. The species is being squeezed by a warming trajectory it cannot adapt to at the pace the ice is retreating.

Emperor penguins are the largest penguin species and among the most recognizable animals on the planet — which makes the listing a symbolic moment as much as a conservation one. The species’ entire existence is organized around sea ice timing. They need it to arrive early enough and last long enough each year. As that window narrows, chick survival rates fall.