Emperor penguin populations in Antarctica have shrunk by almost a quarter as global warming transforms their icy habitat, according to new research on Tuesday that warned the losses were far worse than…

Scientists monitoring the world’s largest penguin species used satellites to assess sixteen colonies in the Antarctic Peninsula, Weddell Sea and Bellingshausen Sea, representing nearly a third of the global emperor penguin population.

What they found was “probably about 50-percent worse” than even the most pessimistic estimate of current populations using computer modelling, said Peter Fretwell, who tracks wildlife from space at the British Antarctic Survey (BAS).

Researchers know that climate change is driving the losses but the speed of the declines is a particular cause for alarm.