The emperor penguin and Antarctic fur seal have been listed as endangered species, the International Union for Conservation of Nature (IUCN) announced on Thursday.

The emperor penguin has moved from "Near Threatened" to "Endangered," while the Antarctic fur seal has moved from "Least Concern" to "Endangered" on the IUCN Red List of Threatened Species.

According to the IUCN, climate change in Antarctica is leading to changes in sea ice that are projected to cause the emperor penguin population to halve by the 2080s.

Emperor penguins require fast ice, which refers to sea ice that is "fastened" to the coastline, ocean floor or grounded icebergs, as habitat for their chicks and during their moulting season, when they are not waterproof.

The organization said that the early break-up and loss of sea ice constitute the primary driver of the population decline of emperor penguins.

It noted that satellite images show a loss of around 10% of the population between 2009 and 2018 alone, equating to more than 20,000 adult penguins.

Meanwhile, the population of the Antarctic fur seal has declined by over 50% since 1999, said the IUCN.

Rising ocean temperature and shrinking sea ice are forcing krill into deeper, colder waters, reducing food availability for seals, the organization explained.

"These important findings should spur us into action across all sectors and levels of society to decisively address climate change. The declines of the emperor penguin and Antarctic fur seal on the IUCN Red List are a wake-up call on the realities of climate change," IUCN Director General Grethel Aguilar said in a statement.

Headquartered in Gland, Switzerland, the IUCN is an international non-profit nature conservation organization.