Record melting of ice cap is latest sign of extreme warming

An iceberg melts in Kulusuk, Greenland near the arctic circle, Aug. 16, 2005. (AP / John McConnico)

The Greenland ice cap has already broken a record for cumulative melting with a month left to go in the season, the latest indication of a year of extraordinary change across the Arctic.

"This is becoming more and more of a trend in the past years," said New York City College's Marco Tedesco, who released the data revealing the strength of this year's Greenland melt season on Wednesday.

Using microwave satellite sensors, Tedesco compiles what's called the cumulative melting index -- a figure that incorporates the number of days of melting on the vast ice cap and the area that's melting.

On Aug. 8, that index pushed past the previous record from 2010, despite earlier figures that included data into early September, when the melt season generally ends. With another four weeks to go, this year's cumulative melt is likely to smash the old mark by a considerable margin.

The news comes on top of data released by NASA in July that showed melting on the ice cap is the most widespread it's ever been in 33 years of satellite records. Imagery showed melting was occurring on 97 per cent of the cap's surface.

As well, there's less snow than ever before, which exposes more ice to warmer air and allows its darker colour to absorb more sunlight.

Scientists won't be able to calculate how much ice the cap has actually lost until the end of the melt season, but Tedesco said that's also likely to break records.

"Up to the end of July, the mass loss was already below the 2010-2011 record," said Tedesco. "We are heading into a direction that is likely a new record."

The National Snow and Ice Data Center in Colorado shows sea ice levels across the Arctic are well below where they were at this point in time in 2007, the lowest year on record. A new all-time low later in September is considered likely.

Even the weather is edging into uncharted territory.

"We aren't seeing more frequent storms, but we are seeing more intense storms," said Matthew Asplin, a post-graduate student in Arctic climatology at the University of Manitoba.

He points to an Arctic cyclone that reached near-hurricane wind speeds and, at its peak on Aug. 6, covered two-thirds of the Arctic Ocean. Scientists are already calling it The Great Arctic Cyclone of 2012.

"In my brief five-year history of working in the Arctic, I haven't seen anything like it," Asplin.

Get used to it, said David Barber, a leading expert on Arctic systems, who also based at the University of Manitoba.

"It's an accumulation of things that have been going on for quite a while," he said. "You get some years that are more dramatic than other years and we're going through a dramatic one."

What's more, the changes reinforce each other.

Less ice means darker-coloured seawater absorbs more sunlight, which in turn melts more ice. Warmer, more open oceans create conditions which contribute to more powerful storms. More powerful storms break up more ice, which increases the pace of melting.

Climate change in the Arctic is now accelerating at a speed outstripping the ability of science to predict it, said Barber. Nor is it likely to stop.

"We're just getting going. We're just getting into this."

Barber said Canadians are going to have to come to grips quickly with the new reality. He said a more accessible Arctic and the increased worldwide demand for resources is going to put more pressure on a part of the world that is still poorly understood.

Vessel traffic is already increasing.

There were 16 large-vessel transits of the Northwest Passage in 2008, reports the Coast Guard. Although some of the increase is due to new mandatory registration requirements, that figure had grown to 38 by 2011.

There are 39 vessels reporting to the Coast Guard in the Passage this week. As resource projects such as the Baffinland mine project begin, that number is expected to keep swelling.

Tedesco added the implications of the disappearing sea ice and declining Greenland ice cap reach beyond one country.

"It modulates climate for the whole Earth," he said.

"It's extremely, extremely interesting. Besides, of course, shocking."