Arctic sea ice area and volume have collapsed in recent decades. And the North Pole has been freakishly warm this winter, as carbon pollution has made what would have been once-in-1,000-years heatwaves increasingly commonplace.
But what’s so remarkable about this year is that the ongoing drop in Arctic sea ice has been matched by an unexpectedly sharp drop in Antarctic sea ice.
A new animation from Kevin Pluck shows just how unprecedented this is:
Final version of the Global Sea Ice Area spiral plot #climatechange #globalwarming pic.twitter.com/TfJYuvEwrZ
— Kevin Pluck (@kevpluck) January 5, 2017
Climate models have always predicted that human-caused warming would be at least twice as fast for the Arctic as for the planet as a whole thanks to Arctic amplification — a vicious cycle that includes higher temperatures melting highly reflective white ice and snow, which is replaced by the dark blue sea or dark land, both of which absorb more solar energy and lead to more melting.
Systems with amplifying feedbacks tend to have tipping points beyond which change is irreversible. In the case of the great polar ice sheets that will drive catastrophic sea level rise and ultimately inundate every major coastal city, we appear to be dangerously close to such tipping points.
Alarmingly, what happens in the Arctic does not stay in the Arctic. The accelerated loss of Arctic sea ice drives more extreme weather in North America, while speeding up both Greenland ice sheet melt (which causes faster sea level rise) and the defrosting of carbon-rich permafrost (which releases CO2 and methane that each cause faster warming).
That’s why, despite President-elect Trump’s vow to kill the Paris climate deal, we are morally obligated to fight to preserve domestic and global climate action.