TORONTO — A study by the global conservation group World Wildlife Fund says that climate change is having a greater impact in the Arctic than was previously thought.

The report is being unveiled at the meeting of the Arctic Council, an intergovernmental forum of Arctic nations Thursday in Norway. WWF says the new report represents the most wide-ranging view of the situation since the Arctic Climate Impact Assessment was published in 2005.

The study finds that the melting of the Greenland Ice Sheet and Arctic sea ice is "severely accelerated." Expert scientists believe it's to such a degree that they're discussing whether both are at their tipping point - where natural systems can face sudden, rapid and possibly irreversible change.

One aspect of the report dealing with summer Arctic sea ice shows that in 2007, it shrank to 39 per cent below its 1979 to 2000 mean, the lowest for the entire 20th century.

WWF Canada Director of Species Conservation, Dr. Peter Ewins, says new evidence in the report shows polar bears could face even earlier regional extinctions and that Prime Minister Harper must make a firm commitment to preserve the species.