US Secretary of State Hillary Clinton took a first hand look Saturday at the way a warming climate is changing the Arctic, opening a once frozen region to competition for vast oil reserves.

Experts here estimate the value of the Arctic’s untapped oil alone — not including natural gas and minerals — at $900 trillion, making it a huge prize for the five countries that surround the Arctic if they can reach it.

And with climate warming opening up some 46,000 square kilometres (18,000 square miles) a year that had once been bound in ice, the region is expected to burst open, not just with oil exploration but with East-West trade along a more accessible northern route.

Returning from a tour of the Arctic coastline aboard a Norwegian research trawler with scientists and government officials, Clinton told reporters that she learned “many of the predictions about warming in the Arctic are being surpassed by the actual data.”

The United States wants to see that change managed by the Arctic Council, an advisory group composed of the Arctic’s closest neighbours, even as other countries are drawn to the region for oil, gas and trade.

The council has its headquarters in Tromsoe, a university town of 70,000 people inside the Arctic Circle that is now emerging as a hub for research and increasingly oil and gas exploration of the region.

Despite worries that a thawing Arctic could set off a “great game” among powers seeking to carve out their slice of undersea riches, experts here say that under the Law of the Sea only five countries can lay claim to most of it.

They are Russia, which has about half the Arctic coastline, Canada, Norway, Denmark and the United States.

Each has a coastline on the Arctic giving it exclusive economic rights to all undersea resources going out 200 nautical miles. Beyond that limit, they can lay claim to the rights to the seabed as far as the continental shelf extends from their territory.

In the case of those five countries, experts here estimate that their seabed rights together will encompass more than 90 percent of the Arctic, leaving a small central portion as high seas open to other comers.

Norway has already won UN approval for its claim to Arctic seabed and has begun producing oil in some areas. Russia’s claim was rejected for lack of detailed documentation, but it is expected to return to the UN authority that manages the process with its claims this year or next.

The United States is not a signatory to the Law of the Sea Convention, so must wait for everyone else’s claims to be adjudicated, a process that officials say could take 15 years, delaying development of its area.

But even countries with no territorial claim to the Arctic are being drawn to the region because, as the ice melts, northern shipping routes are opening between Europe and Asia that cut the distance between them by 40 percent.

A big player is expected to be China, which already has made overtures to Greenland and Iceland, seeking not just access to minerals like rare earth and energy but also ports as its extends its trade lines across the Arctic.

Analysts believe that as much as 70 percent of the trade that could in the future move across the Arctic between Europe and Asia will be to and from China.

Currently, that trade is tiny — just four ships two years ago and 32 ships last year — but some officials expect it to grow exponentially with as many as 600 to 700 ships a year by 2013.

And US officials believe that the thawing of the ice has significant military implications since more naval and air assets will be needed to protect sea lanes and other strategic interests.

Gjoerv, however, says fears of military conflict over the Arctic’s riches are overblown, because so many players have a strong interest in cooperating with each other.