Record high Antarctic temperatures spark global sea rise worries

View of Orne Harbour in South Shetland Islands, Antarctica, on November 27, 2019.
View of Orne Harbour in South Shetland Islands, Antarctica, on November 27, 2019. © Johan Ordonez, AFP
Text by: Henrique VALADARES
5 min

Temperatures in Antarctica hit 20.75°C on February 9, according to a team of scientists on Seymour Island, marking the first time the Polar continent has broken the 20°C barrier. Its warming reinforces concerns that melting ice could raise global sea levels by dozens of metres.

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"We've been monitoring temperatures here for the past 18 years and I never even dreamed that I would one day see such high temperature in the region," Marcio Francelino, Brazilian professor and responsible for the Seymour Island station, told Brazilian newspaper Estado de São Paulo.

On February 9, the Antarctic became the latest region to break a new temperature record, two days after an already alarming peak, when the mercury hit 18.3°C at the Argentinian Esperanza research base. The United Nations had then urged countries to act, after what was already the highest reading on the continental Antarctic Peninsula.

"It's simply a signal that something different is happening in the area," scientist Carlos Ernesto Schaefer told AFP. Because "we can't use this to anticipate climate changes in the future".

 

'Incredible and abnormal'

"We'd never seen a temperature this high in Antarctica," said Schaeffer, who works on a Brazilian government project which monitors the impact of climate change on permafrost and biology in sites across the Atlantic. He described the new record as "incredible and abnormal".

According to British Newspaper the Guardian, the new records still need to be confirmed by the World Meteorological Organization, but they are consistent with the local trend. The peninsula and nearby islands have seen their average temperature rise by almost 3°C since pre-industrial era, one of the fastest rates in the planet.

Although researchers have struggled to link individual events to climate change, scientists' scenarios have proven right so far.

Antarctic more vulnerable to sea rise

Even taken individually, the latest temperature spike in the Polar continent is bad news.

According to a new study published February 12 by Australian researchers in the PNAS journal, Antarctica's vast western ice sheet is extremely vulnerable to sea rises.

They identified a gap in the ice sheet record between 129,000 and 116,000 years ago, meaning there had already been a melting during this period. A second one could be faster, since the previous one "was likely caused by less than 2°C ocean warming", said Christ Turney, professor in Earth and Climate Science at UNSW Sydney and lead author of the PNAS study.

Poles warming faster than rest of the world

The last decade was officially the hottest, according to records, with the last five years being the warmest ever. January 2020 was the hottest January ever witnessed.

The Earth's poles have also been warming faster than the rest of the world. Since 2006, 430 tons of ice have melted in the Arctic area and in Greenland, according to the Brazilian newspaper Folha de São Paulo.

The Brazilian scientists working on the Antarctic programme say this new temperature record appears to be influenced by changes in ocean currents but also by El Niño events.

"Many currents are dependent on cold waters coming from the Antarctic. So this kind of phenomenon causes others, and it generates turbulences in the Austral Ocean, which affects the atmospheric dynamic. The whole thing is very interrelated," Schaefer told G1.

Sea could rise by 60 metres

According to a study published on February 14 in the Earth System Dynamics review, Antarctic melting could raise sea levels by 58 centimetres by the end of the century.

But the region stores about 70 percent of the world's fresh water stock in the form of snow and ice, according to the Guardian. In case it were all to melt, sea levels could rise not only by 58 centimetres but rather by 50 to 60 metres.

"The 'Antarctica Factor' turns out to be the greatest risk, and also the greatest uncertainty, for sea-levels around the globe," lead-author Anders Levermann from the Potsdam Institute of Climate Impact Research told AFP. It could have unpredictable consequences, threatening more than one billion people living in vulnerable areas.

Temperatures in eastern and central Antarctica are relatively stable, but this might not be the case for its Western part, past the Seymour Islands. Its Thwaites and Pine Island glaciers could melt rapidly in case of a sustained jump in temperature.

The team behind the Australian study said that rapid cuts to carbon emissions, such as stipulated in the 2015 Paris Agreement on climate change, could help limit the loss of ice-sheet and slow the process.

But emissions creep higher every year. The world is therefore likely to have to face significant challenges to communities living at low-sea level by 2100.

"What we know for certain is that not stopping the burning of coal, oil and gas will drive up the risks for coastal metropolises from New York to Mumbai, Hamburg or Shanghai," Levermann said.

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