Antarctica’s Emperor penguins are facing dramatic declines by the end of the century and should be given endangered species status because of the threats posedby climate change, according to an international group of scientists. If sea ice declines at the rates projected by current climate models, at least two-thirds of the colonies will likely shrink by more than 50 percent by 2100, the researchers report in Nature Climate Change. That conclusion follows a 50-year study in eastern Antarctica of Emperor penguins, an iconic Antarctic species with 45 known colonies. Emperor penguins’ survival is highly dependent on sea ice concentrations because they breed on the ice, and too little sea ice reduces the habitat for krill, a critical food source for the penguins. Granting the species protected status under the U.S. Endangered Species Act will provide tools for improving fishing practices of U.S. vessels in the Southern Ocean and potentially for reducing CO2 emissions in the U.S. under the Clear Air Act, the researchers say.