WASHINGTON, AUGUST 04

With climate change threatening the sea ice habitat of Emperor penguins, the U.S. Fish and Wildlife Service on Tuesday announced a proposal to list the species as threatened under the Endangered Species Act.

"The lifecycle of Emperor penguins is tied to having stable sea ice, which they need to breed, to feed and to molt," said Stephanie Jenouvrier, a penguin ecologist at the Woods Hole Oceanographic Institution.

Research published Tuesday in the journal Global Change Biology found that by 2100, 98% of Emperor penguin colonies may be pushed to the brink of extinction, if no changes are made to current rates of carbon emissions and climate change.

Around 70% of colonies will be in danger sooner, by 2050.

The new study looked at overall warming trends and the increasing likelihood of extreme weather fluctuations due to global warming. And it noted that extremely low levels of sea ice in 2016 led to a massive breeding failure of an Emperor penguin colony in Antarctica's Halley Bay.

That year, seasonal sea ice broke up before penguin chicks had time to develop waterproof adult feathers, and about 10,000 baby birds drowned, Jenouvrier said. The colony did not recover afterward.

Emperor penguins breed exclusively in Antarctica during winter. They endure temperatures of minus 40 degrees Fahrenheit (minus 40 degrees Celsius) and wind speeds approaching 90 miles (144 kilometers) per hour by huddling together in groups of several thousand birds. But they can't survive without sufficient sea ice.

"These penguins are hard hit by the climate crisis, and the U.S. government is finally recognizing that threat," said Sarah Uhlemann, international program director at the nonprofit Center for Biological Diversity.

The U.S. government has previously listed species outside the country as threatened, including the polar bear, which lives in Arctic regions and is also imperiled by climate change and sea ice loss.

Emperor penguins - the world's largest penguins - currently number about 270,000 to 280,000 breeding pairs, or 625,000 to 650,000 individuals. The proposed listing will be published in the Federal Register on Wednesday to open to a 60-day public comment period.

Listing the bird provides protections such as prohibition against importing them for commercial purposes. Potential impacts on penguins must also be evaluated by U.S. marine fisheries currently operating in Antarctica.

"Climate change, a priority challenge for this Administration, impacts a variety of species throughout the world," said Martha Williams, principal deputy director of the wildlife service. "The decisions made by policymakers today and during the next few decades will determine the fate of the Emperor penguin."