Climate change could spell the end for emperor penguins by the year 2100—that’s the somber prediction of a new international study.

If current warming trends continue, emperor penguins will be marching toward an 86 per cent population decline by the end of the century, at which point, “it is very unlikely for them to bounce back,” says study author Stephanie Jenouvrier, a seabird ecologist from Woods Hole Oceanographic Institution.

Emperor penguins, the largest penguin species on Earth, require sea ice of a specific type to survive. It must be fixed to Antarctica’s shoreline, but also extend far enough into the open sea to allow for foraging. Without sea ice, emperor penguins are unable to raise their chicks and numbers plummet.

By combining two computer models, researchers mapped future sea ice distribution and modelled how the penguin population would respond to changing ice conditions under three different climate scenarios.

If humans limit warming to 1.5ºC, as proposed in the Paris Agreement, sea ice will only decrease by five per cent, leading to a 19 per cent drop in emperor penguin numbers by 2100. Under a 2ºC warming regime, sea ice loss triples and 31 per cent of the population is lost. The worst case—guaranteed extinction—arises if no action is taken and current warming is allowed to continue unabated.

“If we don’t hit the Paris Accord emissions goals,” says Michelle La Rue, study co-author from the University of Canterbury, “emperor penguins are in deep trouble.”