Sea ice levels in the Arctic and Antarctic are growing at a record-slow pace this season, according to multiple sources. While this year’s summer low for the northern hemisphere wasn’t as bad as the current record, set in 2012, the autumn rebound is falling well short of both the fall of 2012’s growth rate and the 37-year average. The Antarctic is following suit, with the summer melt shrinking the ice there at a record speeds.
"It looks like, since the beginning of October, that for the first time we are seeing both the Arctic and Antarctic sea ice running at record low levels," explains Walt Meier, a researcher with NASA’s Goddard Space Flight Center’s Cryospheric Sciences Laboratory. Data for sea ice levels extend back to when they were first gathered in 1979.
While average sea ice levels have been declining sharply in the Arctic over the past decade, ice levels in the Antarctic have remained remarkably resilient, despite the increase in observed ocean temperatures in the southern seas, making this season’s decline a surprise for researchers. While the melted water from this ice doesn’t mean an immediate jump in sea levels, as the ice that had melted was already displacing the water it was sitting in, this is a symptom that both poles are warming up.
Temperatures in the Arctic have seen a massive spike as of late, with air temperatures 20ºC (35ºF) above normal. Despite the region transitioning into a season of long-term darkness, temperatures that would normally be -32ºC (0ºF) are closer to 0ºC (32ºF), preventing seasonal ice from building.
Less ice at the poles also creates a problematic feedback loop, causing the Earth to heat up faster: “As the ice area gets less, you’re changing the albedo of the earth, which is the fraction of solar radiation that gets reflected straight away back into space, so you’re absorbing radiation which warms the earth quicker creating a feedback effect as the ice retreats,” explains Cambridge University’s polar ocean physics group leader, professor Peter Wadhams.
“The only secure way of stopping the sea ice to retreat is stopping warming the climate and that is really by reducing our carbon dioxide emissions.”