A less than two degree Celsius rise in global temperatures might be sufficient to spark a meltdown of the Greenland Ice Sheet and Arctic sea ice, the WWF warned in a new study released Thursday.

"Scientists now suggest that even warming of less than 2 degree Celsius might be enough to trigger the loss of Arctic sea ice and the meltdown of the Greeland Ice Sheet," the WWF said in a statement to accompany the findings.

"As a result, global sea levels would rise by several metres, threatening tens of millions of people worldwide."

The melting of Arctic sea ice could affect ecosystems, while a meltdown of the Greenland Ice Sheet could lead to a sea level rise of up to seven metres, with a devastating impact for the rest of the world.

The WWF urged governments meeting for UN climate talks in Poland starting Monday to "develop a strong negotiation text for a new climate treaty" due at the end of next year.

Kim Carstensen, WWF Global Climate Initiative leader said: "The early meltdown of ice in the Arctic and Greenland may soon prompt further dangerous climate feedbacks accelerating warming faster and stronger than forecast.

"Responsible politicians cannot dare to waste another second on delaying tactics in the face of these urgent warnings from nature."