The world’s great shipbuilders are poring over designs for ice-breaking supertankers. Canada is spending billions on gunboats. Last week Russia planted its flag on the seabed beneath the North Pole.

The next cold war has already started and this one will be frozen. The battle for the mineral treasures of the Arctic will not only last for decades, it will be fought in temperatures below -40C, amid bone-chilling blizzards and unrelieved winter darkness.

The submarine stunt by Russian explorers intent on staking Moscow’s Arctic claim has provided a jolt of urgency to international efforts to protect and administer what one American admiral described as “the last great unexplored bastion on earth”.

The political powers of the northern hemisphere are suddenly facing tense negotiations over who gets what in an oil and gas-rich polar territory twice the size of France. Two miles under the Pole, Artur Chilingarov, a Russian explorer and politician, dropped a rustproof titanium flag from the hold of a mini-submarine to prove that while Moscow lost the space race, it is determined to win the ice race.

At stake in this outbreak of polar posturing is not just patriotic pride, but access to what geologists believe are a quarter of the globe’s oil and gas reserves - in short, the solution to the crippling energy shortages that will begin throttling western economies within the next two decades.

A potent combination of global warming - causing the Arctic ice-cap to melt - and developing extraction technologies is unlocking the door to hydrocarbon deposits that had long seemed inaccessible. Scientists believe climate change may open up a key Arctic shipping route - the fabled Northwest passage linking the Pacific and Atlantic oceans - to routine maritime traffic by 2050.

“Experts say after 2016, oil production will drop tremendously,” said Anatoly Opekunov, deputy director of Russia’s Research Institute for Ocean Geology and Mineral Resources. “Every country, including Russia and the US, is thinking about this.”

In Washington last month, a group of US civilian and military agencies held a three-day meeting to discuss the economic, ecologi-cal and political consequences of increasing Arctic exploration.

“This is an ocean explorers have sought routes through for 500 years,” said Mead Treadwell, head of the US Arctic Research Commission. “If there is to be an international regime in the Arctic, it’s time to think about that.”

Oil companies are already pondering the technical challenges of industrialising one of the world’s great wildernesses. Recent geological studies indicate that up to 80% of the energy reserves may be natural gas.

“The cost of getting the gas out of the ground is high, but the cost of getting it to anywhere useful is even higher,” said Andrew Kendrick of BMT Fleet Technology, a firm that specialises in Arctic exploration.

A recent article in Professional Engineering magazine noted that Arctic pipelines were “out of the question” because they would be prohibitively expensive to lay. “The only viable way of transporting is going to be over the sea, using gigantic tankers full of liquefied natural gas,” the magazine said.

The prospect of giant ice-breaking tankers carrying highly explosive gas and roaming the iceberg-filled Arctic at speed is unlikely to reassure environmentalists opposed to any exploitation of pristine polar territory.

Yet President Vladimir Putin’s commitment to establishing Russia’s Arctic primacy - he personally telephoned Chilingarov and his crew to congratulate them last week - leaves other countries little option but to join the race or be left in the cold.

Russia already controls the world’s largest reserves of natural gas and is second only to Saudi Arabia in oil production. Both European and American officials are concerned that the West may be forced into politically damaging dependence on Russian energy production if Moscow’s claim to 463,000 square miles of Arctic is not challenged.

International lawyers agree that Russia’s claims have no more legal basis than Canada’s claim to the Northwest passage, which is regarded by most other countries as international waters.

Stephen Harper, the Canadian prime minister, last month announced plans to spend £3.4 billion on at least six ice-breaking patrol ships to maintain Canada’s claim to the passage. Last week Peter MacKay, Harper’s foreign minister, denounced the Russian stunt. “This isn’t the 15th century,” he said. “You can’t go around the world and just plant flags and say, ‘we’re claiming this territory’.”

Yet Eric Posner, professor of law at the University of Chicago, concluded that the small print of international maritime agreements was likely to prove irrelevant in the Arctic. “Power, not international law, will settle the issue,” he said. “Russia’s expression of power is credible; Canada’s is not.”

At stake are an estimated 500 billion barrels of oil, incalculable volumes of natural gas and potential deposits of diamonds, platinum, nickel, tin and gold.

US scientists have long been aware of the Arctic’s mineral potential, but fierce opposition in Washington to drilling in Alaskan wildlife refuges has hampered exploitation. The Americans have also been slow to grasp the implications of climate change and several officials complained last week that Putin had seized the strategic initiative.

A recent report by the US Centre for Naval Analyses described global warming as a “serious threat” to US security that should become a military priority.

Additional reporting: Felix von Geyer, Montreal, and Kevin O’Flynn, Moscow

WORLD WATCH

Who owns the North Pole? No one does. But five countries have territory inside the Arctic Circle: Russia, America (through Alaska), Canada, Denmark and Norway control economic rights within 200 miles of their borders. The question under international law is whether there might be geographical, geological or political reasons why one country’s rights should be extended.

So what’s the basis of Russia’s claim? Whatever you think of President Vladimir Putin, he has played a cool Arctic hand. Moscow is attempting to prove that an underwater Arctic formation known as the Lomonosov Ridge is actually a continuation of a Siberian peninsula. Last week’s submarine expedition was searching for geological samples that would extend Russia’s claim to vast swathes of oil and gas-rich territory.

Why doesn’t America step in? Washington has made a polar bear’s breakfast of its own Arctic claims. The Americans are unhappy with both Russia and Canada, which has claimed rights over the Northwest Passage, the mostly icebound but fast-melting link between the Atlantic and Pacific. Yet conservative Republican distaste for any United Nations agreements has prevented the US from ratifying the Law of the Sea Treaty, the most logical international forum for settling Arctic disputes.

Talking of polar bears, what does all this mean for them? The main threat is still global warming, which is shearing off sections of the ice cap at a rate of about 9% each decade. Compared with the threat of shrinking habitat, a few dozen drilling platforms shouldn’t affect the local wildlife too much. But any oil spills would spell trouble for the animals. And if a gas-filled supertanker runs into an iceberg, you might feel the explosion in Chelsea.

Is it worth the superpower angst? Look at it this way. Oil is currently around $70 a barrel. There may be 500 billion barrels of oil hidden under the Arctic. So is it worth another cold war? That’s a $35,000 billion question.

When do I need to start worrying? Arctic exploration can’t happen in a hurry. The environment is too hostile, the economics too daunting and the pace of development too slow for serious exploitation before, say, 2050.

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