The sea ice extent is one of the key components of the polar climate system. As global warming is changing the landscape of the Arctic, scientists are expectant as to what’s shaping up to be a new record at the other end of the globe: an apparent alarming decline in Antarctica’s sea ice cover.
1. Record year
Fears that Antarctica’s ice cover is disappearing quicker than expected are based on preliminary data from the National Snow and Ice Data Center (NSIDC), which suggests that the South Pole will likely set a record this year for the lowest sea ice extent. On 16 February, the sea ice around the continent dropped lower than the previous record minimum set in March 2017.
What’s going on in the Antarctica is an extreme event. But we’ve been through this a bit.
Ted Scambos, glaciologist at the University of Colorado Boulder and lead scientist at NSIDC
Unlike the Arctic, where scientists blame climate change for the acceleration of melting ice, Antarctica’s sea ice extent is highly variable. Sea ice at the South Pole grows and shrinks every year. “There’s a link between what’s going on in Antarctica and the general warming trend around the rest of the world, but it’s different from what we see in mountain glaciers and what we see in the Arctic,” Scambos said.
2. Satellite tracking
Based on the EU’s satellite service Copernicus, the monthly average Arctic sea ice extent in June 2021 was 11.2 million km2 , 3% below the 1991-2020 average for June. This value ranks as the 8th lowest for June in the satellite’s data record, which started in 1979, and is close to the values seen in 2017 and 2018. Going back to 1978, satellite data further shows that the region of Antarctica was still producing record-high sea ice extent as recently as 2014 and 2015, according to CNN. Then it suddenly plunged in 2016 and has stayed lower-than-average since.
According to the Royal Society, after 2014, Antarctic ice extent began to decline, reaching a record low — within the 40 years of satellite data — in 2017 and remaining low in the following two years.
That kind of drop is pretty much unprecedented in the record. Antarctic sea ice does vary from year to year, but that was a bigger variation than what normally happens.
Marilyn Raphael, geography professor and director at UCLA’s Institute of the Environment and Sustainability, quoted by CNN
Scientists say the recent shift doesn’t yet necessarily mean that a long-term trend is on the horizon. However, Raphael said the sea ice is retreating earlier now, which can be concerning.
“There are two parts of me that answer this — the scientist part says, ‘wait a little bit longer and see.’ That’s my cautious part,” Raphael said. “Then the other part of me says, this is an unusual variation in the ice. The degree is unusual, and it could be that that’s a sign that climate is changing, and that’s the speculation part,” the scientist concluded.
3. Research stations and tourism
Research stations and tourism are also likely to play its part in the melting of the ice, especially in the summertime, which is between November and March in Antarctica.
When the snow becomes a bit darker, it absorbs extra solar radiation. That extra energy facilitates the melting of the snow.
Raúl Cordero, Researcher at the University of Santiago, Chile
Together with his colleagues from the University of Santiago, Chile, Raúl Cordero decided to measure the impact of black carbon pollution on the snow in Antarctica. He went on explaining that he black carbon that settles on the snow can accelerate its melting. According to the New Scientist, they believed that pollution from increasing human activity in Antarctica has been darkening the snow, causing it to melt sooner than usual near research facilities and popular tourist sites.
