65% of Antarctica's Plants and Wildlife Will Decline by 2100, Study Finds

The impact of the man-made climate crisis on Antarctica is scientifically undeniable: stable ice shelves are retreating, air temperature increased by 3 degrees Celsius, krill numbers are declining, melting ice is contributing to sea level rise, and polar bears and seals are getting displaced. Now, a new study adds further insight into the plight: Existing conservation efforts are insufficient to protect Antarctic ecosystems.

Published in the journal PLOS Biology, the study finds population declines are likely for 65% of the continent's plants and wildlife by the year 2100.

"Antarctic biodiversity could decline substantially by the end of the century if we continue with business as usual," Jasmine Rachael Lee, lead author of the University of Queensland study, tells Treehugger.

"This is the first time anyone has carried out a comprehensive and continent-wide assessment of how vulnerable Antarctic species are to threats and what we can do about it."

The most vulnerable species is the Emperor penguins (Aptenodytes forsteri)—the only species in the study that could be extinct by 2100.

In October 2022, the U.S. Fish and Wildlife Service listed Emperor penguins as a threatened species under the Endangered Species Act, as experts predict the flightless seabird will see a 26% to 47% dip in its population by 2050. “This listing reflects the growing extinction crisis and highlights the importance of the ESA and efforts to conserve species before population declines become irreversible,” said Service Director Martha Williams at the time. “Climate change is having a profound impact on species around the world ... the listing of the emperor penguin serves as an alarm bell but also a call to action.”

Lee says Emperor penguins are a "keystone species" in the marine environment and a "vital link" in the Antarctic food chain. "They control populations of small fish and crustaceans and provide an essential food source to higher predators (e.g., killer whales and leopard seals)," she adds. "The emperor penguin usually breeds on ice (making it especially vulnerable to climate change), but Adélie, chinstrap, and gentoo penguins breed on rocky outcrops—their penguin poo (guano) provides essential nutrients to the terrestrial ecosystem that helps it thrive. Plants, moss, and invertebrates all rely on these marine sources of nutrient input."

Aside from Emperor penguins, "other Antarctic specialists, like the Adélie penguin and dry soil nematodes, were also highly vulnerable," says Lee. That said, not all species will decline. According to Lee, "some are expected to even benefit from climate changes, at least initially." These include two native Antarctic plants (Colobanthus quitensis and Deschampsia antarctica) and the Gentoo penguin.

"It doesn’t have to be this way; we can prevent the worst of the changes if we take global action on climate change this decade," says Lee. "This will help to save our iconic species like the emperor and Adelie penguins, and all of Antarctica’s unique and highly adapted inhabitants. It will also help humankind, as we rely heavily on the priceless services the Antarctic provides in regulating our climate and capturing sea level in its ice sheets."

As for what is the best conservation strategy, the study found mitigating climate change will have the greatest impact.

"We urgently need a combination of global and local conservation action to best conserve Antarctic species. Global action and global voices to help mitigate climate change—because the biggest threat to Antarctica is coming from outside of it," says Lee. "And then we need local actions to help protect biodiversity against local threats and give them the best chance of adapting to climate changes. Some of the local ones, like 'minimizing the impacts of human activities,' are cheap, feasible, and beneficial, so we should try to implement these ASAP."

"We now have a roadmap to carry us forward, with the details on which conservation actions we need to implement to conserve these species into the future."