OSLO (AFP) - The five countries bordering the Arctic – including Norway and Denmark – are ramping up territorial claims in the Arctic as melting ice is opening up new shipping routes and search for oil and gas intensifies.

Rising temperatures are causing the Arctic's ice sheets to melt, opening the door for an economic boom in the region but also posing a major threat to the survival of its indigenous peoples.

The mercury is rising twice as fast in the Arctic as elsewhere, offering a frightening preview of what the future holds for the planet and prompting UN Secretary General Ban Ki-moon to describe the situation as "a canary in a coalmine."

In what is the most visible effect of global warming, the melting ice cap shrank to a record low of 4.1 million square kilometres (1.58 million square miles) in September 2007. It risks disappearing entirely in the summer months by the end of this century, according to experts.

"That's maybe even a bit optimistic given the latest observations, which suggest that the sea ice is melting even faster than expected," said Paal Prestrud, director of the Centre for International Climate and Environmental Research in Oslo (Cicero).

The melting ice is opening up new shipping routes, such as the Northwest Passage off Canada and the Northern Sea route off Russia, which will dramatically shorten routes for ships sailing between the Atlantic and the Pacific, thus avoiding the Panama or Suez canals.

The distance between Rotterdam and Yokohama will be shortened by as much as 40 percent, for example.

Energy groups are meanwhile eagerly eyeing oil and gas riches under the seabed that have long been inaccessible because of the ice -- to the great dismay of environmental activists who fear oil spills in a fragile area.

The region could be home to 90 billion barrels of oil -- worth a whopping 7.0 trillion dollars at the current oil price -- and 30 percent of the planet's untapped gas reserves, according to the US Geological Survey.

The five countries bordering the Arctic (the United States, Canada, Russia, Norway and Denmark through its territory Greenland) have in recent years ramped up their territorial claims in the region, with Russia going so far as to plant its flag 4,000 metres (13,000 feet) beneath the North Pole.