San Francisco Frontiers - Emperor penguins listed as endangered species: IUCN

Its change of status from "near threatened" to "endangered", made by the International Union for Conservation of Nature (IUCN), underscores the existential threat for ice-dependent species as global warming profoundly reshapes the frozen continent.

Emperor penguins rely on stable sea ice -- essentially platforms of frozen ocean water -- to live, hunt and breed.

Their numbers have plummeted as warming driven by greenhouse gas emissions has caused sea ice to break up earlier in the year.

The IUCN -- a global network of scientists, governments and conservation groups -- said changes in sea ice were expected to halve the emperor penguin population by the 2080s.

They "concluded that human-induced climate change poses the most significant threat to emperor penguins", Philip Trathan, part of the IUCN expert group who worked on the Red List assessment, said in a statement.

The Red List of Threatened Species is maintained by the IUCN and is the global reference on the extinction status of plants, animals and fungi.

There are six classifications from "least concern" to "extinct".

Emperor penguins now rank two steps below "extinction in the wild" -- a species surviving in captivity only, and not in nature.

The Antarctic fur seal -- once hunted to near extinction for their pelts -- was also moved to "endangered", their numbers having dropped more than 50 percent since 1999.

"The ongoing decline is due to climate change, as rising ocean temperatures and shrinking sea ice are pushing krill to greater ocean depths in search of colder water, reducing the availability of food for seals," the IUCN said.

- 'Icons on ice' -

The largest and heaviest of the penguin species, boasting a brilliant golden-orange streak on the neck, emperor penguins have become symbolic of the fight to survive in Antarctica's harsh climes.

They breed on the sea ice in the dead of winter, the males keeping their eggs warm beneath their feet.

The frozen surface also provides a habitat for their chicks during moulting season before they are waterproof.

Antarctic sea ice undergoes huge seasonal changes, expanding during winter and shrinking in summer.

But as global temperatures have reached new highs, sea ice has retreated earlier in the spring and become less stable.

Sea ice has been at record low levels since 2016 and the impact on emperor penguins has been well documented.

Satellite imagery indicates around 20,000 adults -- some 10 percent of the population -- disappeared between 2009 and 2018 alone, the IUCN said.

"This species is closely associated with sea ice and ice packs," Christophe Barbraud, a scientist at French research institute CNRS, told AFP.

"However, since 2016-2017, there has been a significant decrease in the extent of sea ice around Antarctica, and therefore without sea ice, it will have great difficulty surviving."

"The fate of these magnificent birds is in our hands," Rod Downie from conservation group WWF said in a statement.

"With the shocking decline in Antarctic sea ice that we are currently witnessing, these icons on ice may well be heading down the slippery slope towards extinction by the end of this century -- unless we act now."

The IUCN also moved the southern elephant seal from "least concern" to "vulnerable" following sharp population declines caused by a deadly contagious pathogen.

K.Torres--SFF