Nearly all of the world’s emperor penguin colonies may be pushed to the brink of extinction by 2100, a new study has found, as the United States moves to list them as threatened under the Endangered Species Act.

If climate change continues at its current rate, more than 98 percent of emperor penguin colonies are expected to become quasi-extinct by the turn of the century, a group of global researchers wrote in the journal Global Change Biology on Tuesday. The scientists’ near-term predictions were equally grim: They estimated at least two-thirds of colonies would be quasi-extinct by 2050.

(Quasi-extinction refers to a population being doomed for extinction even if some members of the species remain alive.)