The melting of the Arctic ice cap is one of the most foreboding signs of dangerous climate change.
If too much ice melts, it will set off natural feedback loops that warm the planet even faster and disrupt weather patterns.
A month ago, satellite data from the US National Snow and Ice Data Center (NSIDC) suggested the Arctic sea ice was growing back. In early April, the ice cover was close to the 30-year average.
But in recent weeks, the NSIDC has recorded a rapid drop in ice cover. By late May, the ice cover had dropped below what it was in May 2007 — the lowest year on record.
By September 2007, the ice cap had retreated to 40% below the average. The news sent shockwaves through the scientific community. The melt rate this year is on track to break this record.
The NSIDC’s Mark Serreze told news agency Canadian Press on May 19: “Could we break another record this year? I think it's quite possible.
“We are going to lose the summer sea-ice cover. We can’t go back.”
Scientists say the ice is melting back so quickly because it’s now much thinner than before.
Sea-ice expert David Barber, of the University of Manitoba, told CP about only 18% of the ice cap now consists of thick, multi-year ice. In the early 1980s, the figure was about 90%.
The new, thin ice is breaking up faster as temperatures rise. April was the hottest month recorded since records began in the 1880s.
Furthermore, warming in the Arctic region has been about two-to-three times above the global average, a February 22 Earthtimes.org article said.
Bizarre weather patterns have been recorded in the Arctic recently. A three-minute rainstorm surprised a scientific group on Ellef Ringnes Island, near the North Pole, in late April.
The team's expedition director, Pen Hadow, told Reuters on April 27: “It’s definitely a shocker ... the general feeling within the polar community is that rainfall in the high Canadian Arctic in April is a freak event.”
Environment Canada’s senior climatologist, David Phillips, told CBC News on April 29: “My business is weird, wild and wacky weather, and this is up there among fish falling from the sky or Niagara Falls running dry.”
Hadow’s team also reported abnormally thin ice and strong winds for that time of year.
NASA glaciologist Jay Zwally told EarthSky.com that studies had confirmed the Greenland ice sheet was also losing ice fast — at a rate of about 150 gigatons a year.
He said: “One way to think about how much 150 gigatons is, [is] that if you had earth movers that carried 150 tons each, it would take 2,000 of them each minute to dump the excess ice into the ocean.”
Zwally said: “The important thing to know about the Earth’s ice sheets is that they are changing, that they are responding to climate change.
“The idea of the canary in the coal mine is that it’s a warning sign to get out of the coal mines when the gases build up.
“The things that are taking place on the Earth — the melting of the ice sheet in Greenland, the increase and the loss of sea ice in the Arctic ocean — these are warning signs of the same type.”