From Aftenposten: 

Nalan Koc, a senior researcher who leads an Arctic climate program at the Norwegian Polar Institute in Tromsø, told Aftenposten that the melting tempo has suddenly increased.

There are four weeks left before the annual ice melting season officially ends in the Arctic. Last year, the melting tempo abruptly rose in August and September, and now the same thing appears to be happening.

Koc, who's also a professor at the University of Tromsø, said neither she nor her colleagues could explain why the ice is melting more quickly. She said the developments, however, were "dramatic" and "can have major consequences."

Data from American satellites indicate that ice conditions in the Arctic are changing quickly, Koc said. Figures from the National Snow and Ice Data Center in Colorado in the US have shown that the Northwest Passage is now open.

Last fall, around a million square kilometers of ice disappeared in a few weeks. Koc said there's a real danger that with so much ice already melted away, it won't be possible to return to conditions earlier viewed as "normal."

As the ice melts, warmer sunlight warms up the seas. At the same time, warmer waters from the Gulf Stream are being pressed northwards.

The temperature of the Gulf Stream along the Norwegian coast has risen two degrees Celsius in the past 20 years, while the average air temperature around Svalbard has risen four to five degrees.

"We’ve already seen that fjords around Svalbard that normally have been covered with ice in the winter have been ice-free the past few years," Koc said. "The glaciers are shrinking in volume."

It remains unclear, however, why the melting rate has risen so dramatically this month and in August of last year. "We have to learn from the past to understand the future," Koc said. "Now we're facing new challenges."