WHEN writer Anton Chekhov arrived on the Russian island of Sakhalin in 1890, he was overwhelmed by the harsh conditions at the Tsarist penal colony. It wasn't just the floggings, forced prostitution and ill-treatment of children in the colony. It was the environment itself. “There is no climate on Sakhalin, just nasty weather,” Chekhov wrote. “And this Island is the foulest place in all of Russia.” More than a century on, Sakhalin's prisoners have been replaced by oil and gas workers, most of whom seem to agree that Chekhov's description still fits. The sparsely populated island – which is the length of Britain – has some of the most extreme weather on earth. Marine cyclones and violent snowstorms rip through its forested hills, and the ocean waters off its northern coast freeze solid for a good part of the year. In winter, temperatures drop to minus 40 Celsius and snow can pile three metres high. Workers at Exxon's Odoptu oil field, eight km (five miles) off the northeast coast of Sakhalin, had to shovel their way out of their dormitory last winter to clear pipe valves and free oil pipelines of snow. “The blizzards were so bad that at one point we had to evacuate half of the staff,” says Pavel Garkin, head of the field's operations. Now Moscow hopes to attract global oil players to another extreme location: its icy Arctic waters. Shared by Canada, Denmark, Iceland, Norway, Russia and the United States, the Arctic may hold around one-fifth of the world's untapped oil and gas reserves according to a US Geological survey. The past few years have seen a rush of activity in the region, with UK oil explorer Cairn Energy drilling for oil off the west coast of Greenland and Norway's Statoil, one of the world's largest offshore oil producers, pushing further and further up the Nordic country's serpentine coastline, drilling wells inside the Arctic Circle beneath both the Norwegian and Barents Seas. In September, Russia and Norway put an end to a 40-year dispute over maritime boundaries in the Barents Sea, freeing Russia to push for increased exploration under its portion of the waters just three years after the country spelled out its Arctic claim by planting a rust-proof flag on the sea bed more than four km (14,000 ft) under the North Pole. The rewards could be huge. Russia, the world's top oil producer with output of more than 10 million barrels of oil per day (bpd), estimates that its Arctic zone holds around 51 billion tons of oil, or enough to fully meet global oil demand for more than four years, as well as 87 trillion cubic meters of natural gas. Unlike Norway, Russia is not currently producing in its Arctic offshore, but the country's Natural Resource Ministry says it wants to invest at least $312.8 billion by 2039 to explore the shelf. Most of this money will go to the Arctic. But even as Russia opens its northern waters to exploration, there's reason to pause. In the wake of BP's catastrophic leak in the Gulf of Mexico this spring, Russian officials and experts warn an oil spill under the ice could turn out far worse than one in warmer deepwater climates. Arctic conditions – remoteness, fragile ecosystems, darkness, sub-zero temperatures, ice, high winds – make dealing with an oil spill a massive task. At an annual conference for global oil and gas heavyweights held on Sakhalin at the end of September, Russian government officials and offshore industry professionals paid close attention to the dangers of drilling on the Arctic continental shelf. “I have attended 13 of the 14 Sakhalin oil conferences, and this is the first where government regulators were visibly and vocally concerned about offshore oil spill risks,” says Michael Bradshaw, an expert on Russia's Far East energy industry and professor at the University of Leicester. It's not that a spill is more likely in the Arctic than in a warmer, deep-water locale, says Nils Masvie, a director at Norwegian offshore risk-assessment firm Det Norske Veritas. “But you cannot extrapolate and say the risk is the same in a cold climate. No, the risk is higher.” That's because it's so much harder to manage a spill and offshore emergency in the ice and dark. “Sometimes search and rescue operations stop in the evening because it is too dark, resuming again at eight o'clock when the light returns. But if something happens on the Arctic Barents Sea in November it would be, ‘OK, we'll come back for you in March,'” says Masvie, whose company verifies and certifies equipment used in offshore oil and gas production, such as the Nord Stream gas pipeline being built under the Baltic Sea for Russian gas giant Gazprom. Lessons from Komi Russia's track record with oil spills does not inspire confidence. During the 1970s oil boom, primitive production, drilling and pipeline technology caused pollution levels in rivers, oceans, lakes and ground water to soar. In 1975, for example, several large West Siberian rivers that run north through Russia's biggest oil production region and empty into the Arctic Ocean had oil concentrations 21 times the maximum permissible level, according to a government report, “Status of Environmental Pollution in the USSR 1975-1976”. One of the worst spills occurred in August, 1994, when the ageing pipeline network in the northern Komi Republic sprang a leak. The oil spill was officially put at 79,000 tons, or 585,000 barrels, though independent estimates put it at up to 2 million barrels. At the high end that would have been half as big as BP's 4 million barrel Gulf disaster. Two months after the spill started, heavy rains broke a dam that contained the oil, releasing a massive slick into rivers and across forested tundra near the city of Usinsk.