The Antarctic fur seal also was newly labeled as endangered by a key international group, which cited a warming world.

Two iconic South Pole species, the emperor penguin and the Antarctic fur seal, have been officially declared endangered by the world’s leading conservation authority — a consequence of dramatic changes to their habitats caused by global warming.

Emperor penguins were already considered near threatened due to the loss of coastal sea ice, which they rely on for raising chicks. Early ice breakup can lead to colonies falling into the ocean before chicks grow their waterproof feathers, causing the hatchlings to drown.

There are less than 600,000 adult emperor penguins left in the wild, and new projections suggest that the population could fall to half that by the 2080s, according to the International Union for the Conservation of Nature.

“Emperor penguins are a sentinel species that tell us about our changing world and how well we are controlling greenhouse gas emissions,” Philip Trathan, a member of the IUCN specialist group that determined the species’ conservation status, said in a statement Thursday.

A dramatic collapse of the Antarctic fur seal population likewise prompted the IUCN to change the species’s status from “least concern” to “endangered.” The organization said that rising ocean temperatures have pushed the seals’ main prey — krill — to greater ocean depths, making it harder for the seals to find food.

Between 1999 and 2025, the IUCN said, the number of Antarctic fur seals dropped by more than 50 percent.

Grethel Aguilar, the IUCN director general, called the declines of both species “a wake-up call on the realities of climate change.”

Though most humans will never see Antarctica, the frozen continent’s environment and ecosystems are vital to the entire planet. Its sea ice reflects some of the sun’s energy back into space, keeping the Earth cool. Its cold, dense, nutrient-rich waters drive the global ocean circulation system and support some of the world’s most important fisheries.

If emperor penguins and Antarctic fur seals are suffering, Aguilar said, it means that humans should be worried too.