Global warming could reveal lucrative reserves of untapped oil, gas and precious metals beneath the ice caps in the near future - but at what environmental cost? For all the talk among world leaders of the perils of climate change, many are scenting an opportunity. As the Arctic ice retreats, surrounding nations are looking to plunder those natural resources under the surface, estimated by the US Geological Survey to constitute as much as 13 per cent of the worlds undiscovered oil and 30 per cent of its undiscovered natural gas - as well as precious metals including iron ore, gold, zinc and nickel. There is the prospect of a dramatic new shortcut between Europe and Asia, slashing journey times by as much as a third. Last month, two German ships completed their journey along the Russian coast from South Korea to Bremen without any icebreaker escort. There are also hopes that Canadas Northwest Passage could offer a viable alternative to the Suez and Panama canals. The claim-staking and posturing has started: last year, Russia sent a submarine to plant its flag beneath the North Pole; next spring, it plans to drop paratroopers there. But much of the speculation about the Arctics future remains just that - not least the references to the emergence of a trans-Arctic commercial highway that is supposedly going to become ice-free over the next two or three decades. True, the ice is shrinking. The latest findings from the National Snow and Ice Data Centre at the University of Colorado, using remote sensing data from Nasa satellites, showed that the ice levels now stand well below their long-term average: this summers total of 1.97 million square miles is nearly a third less than the average figure for 1979-2000, even if it marginally exceeds the record-breaking lows of the past two years. Yet much of the Arctic Ocean looks set to become ice-free only in late summer, while remaining frozen throughout winter. Over the past 30 years, ice coverage has been decreasing much more rapidly in summer - around 6.2 per cent every decade - than in winter (around 2.6 per cent), and computer models strongly suggest that most of the ocean will remain covered in ice during the winter. - Telegraph