The Antarctic is turning from a fridge for the world – keeping temperatures down – to ‘a radiator’, scientists warned yesterday.
Ice on land and sea in the Antarctic would normally reflect the sun’s rays back into space, but as water forms ponds and lakes on Antarctica, this absorbs heat.
Professor Martin Siegert said the South Pole continent ‘is an enormous, vast white surface…it does an enormous job for the planet in terms of a lot of solar radiation bounced back into space’.
The same process – where ice has melted exposing 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, beating the previous minimum record set last year.
The Antarctic is turning from a fridge for the world – keeping temperatures down – to ‘a radiator’, scientists warned yesterday
A winter heatwave in March 2022 saw temperatures soar nearly 40C above the norm in East Antarctica, from around -50C to -10C, and had it happened in summer it would have began melting the surface of the ice sheets which scientists said they have never seen before.
Professor Siegert said: ‘I think the scientific community has been shocked by this season’s lack of sea ice, so much lower than has happened in previous years’.
Because of Antarctica’s harsh environment and remote location, there is less data available to unequivocally link events like these with human-induced climate change, but scientists say they are to be expected on a warming planet.
Professor Siegert added: ‘I think it’s reasonable to assume that with the Antarctic heat event that we’ve seen, that is the sort of thing that has been expected with global heating because of burning fossil fuels and it has happened.
‘It could be, because we’ve done a lot of scientific evidence, that it was just one of those one-in-1,000 year events, but that’s so unlikely, and I think it’s perfectly scientifically reasonable to make the assumption that it is linked to our heating planet.’
Together with scientists from across the UK, Chile and South Africa, Professor Siegert has been examining evidence of extreme events in Antarctica and said it is ‘virtually 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 that human impacts are changing the Antarctic, from melting sea and land ice, collapse of ice shelves, warming oceans and atmosphere, near-extinction of marine animals and introduction of foreign species such as moss and grass.
Scientists are particularly concerned about what might happen over the next few years as the warming effects of El Nino take hold.
Dr Anna Hogg of the University of Leeds said: ‘As somebody who watches this happen on a day-to-day basis, I’m finding it really surprising and staggering to see the changes occur at the scale that they are already.’ She said it would take centuries for collapsed ice shelves to recover, if it was even possible.
Extreme events such as ice shelf collapse or heatwaves combine in cascading, or multiplying effects that reach across the world but also threaten native species
These collapses do not directly add to sea level rise as the ice is already floating, but it means ice from the land pours into the sea much faster via glaciers, which is speeding up the rate of sea level rise.
If all the ice in Antarctica were to melt, although scientists do not believe this will happen anytime soon, it would push up the global sea level by 57 metres.
Extreme events such as ice shelf collapse or heatwaves combine in cascading, or multiplying effects that reach across the world but also threaten native species.
The team of scientists are calling for more environmental protection measures to be put in place to help conserve increasingly fragile ecosystems that are becoming more exposed.
Melting ice could result in better access for ships which bring more people for example, who therefore must take more care not to bring non-native seeds on their boots.
The UK Foreign Office is looking to give better protection to emperor penguins, who are a ‘climate vulnerable’ species, said the department’s head of polar regions Jane Rumble.
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