Antarctica is changing from a fridge for the world – which keeps temperatures down – to “a radiator,” scientists warned yesterday.
Ice on land and sea in Antarctica normally reflects the sun’s rays back into space, but since water forms ponds and lakes in Antarctica, it absorbs heat.
Professor Martin Siegert said the South Pole continent is ‘a huge, expanse of white surface… it does an enormous amount of work for the planet in terms of a lot of solar radiation being reflected back into space’.
The same process — where ice has melted and exposes the ocean — is already happening in the Arctic, he said.
Professor Siegert, a glaciologist at the University of Exeter, said sea ice around the frozen continent is currently at its lowest level since satellites began observing it in 1979, surpassing the previous minimum record set last year.
Antarctica is turning from a refrigerator for the world – which keeps temperatures down – to ‘a radiator,’ scientists warned yesterday
During a winter heat wave in March 2022, temperatures rose nearly 40°C above the norm in East Antarctica, from about -50°C to -10°C, and had it happened in the summer, the surface of the ice caps have started melting, something scientists said they’ve never seen before.
Professor Siegert said: ‘I think the scientific community is shocked by the lack of sea ice this season, so much less than in previous years’.
Due to Antarctica’s harsh environment and remote location, less data is available to unequivocally link such events to human-induced climate change, but scientists say they are to be expected on a warming planet.
Professor Siegert added: ‘I think it’s fair to assume that with the Antarctic heat event that we’ve seen, that’s the kind of thing that was expected with global warming from fossil fuel burning, and the has happened.
“It could be, because we’ve provided a lot of scientific evidence, that it was just one of those once-in-1,000-year events, but that’s so unlikely, and I think it’s perfectly scientifically reasonable to assume that it is. linked to our warming planet.’
Working with scientists from the UK, Chile and South Africa, Professor Siegert has examined evidence of extreme events in Antarctica and said it is ‘almost certain’ that their severity will increase unless greenhouse gas emissions are controlled.
Publishing their work in the journal Frontiers in Environmental Science, they identified nearly a dozen ways human influences are changing Antarctica, from melting sea and land ice, ice shelf collapse, warming oceans and atmosphere, near-extinction of marine animals and introduction of strange species like moss and grass.
Scientists are particularly concerned about what may happen in the coming years if the warming effects of El Nino take hold.
Dr. Anna Hogg from the University of Leeds said: ‘As someone who sees this happening on a daily basis I find it really surprising and disconcerting to see the changes on the scale they are already taking place.’ She said it would take centuries for collapsed ice shelves to recover, if at all.
Extreme events such as ice shelf collapse or heat waves combine to create cascading or multiplying effects that span the globe and threaten native species
These collapses do not directly contribute to sea level rise, as the ice is already floating, but it means that ice from land flows much faster into the sea via glaciers, accelerating the rate of sea level rise.
If all the ice in Antarctica melted, although scientists don’t believe it will happen any time soon, it would raise global sea levels by 57 metres.
Extreme events such as ice shelf collapse or heat waves combine to create cascading or multiplying effects that extend across the globe, as well as threaten native species.
The team of scientists is calling for more environmental protection measures to help preserve increasingly fragile ecosystems that are increasingly exposed.
Melting ice could lead to better access for ships that carry more people, for example, who should therefore be more careful not to put foreign seeds on their boots.
The British Foreign Office is seeking better protection for emperor penguins, which are a “climate-sensitive” species, said Jane Rumble, head of the polar regions.