The Arctic's formidable natural barriers have deterred most human activity for millennia. But with the ocean expected to be ice-free in summer by 2030, the Arctic is now squarely in the geopolitical spotlight, as powers near and far rush to secure their positions in an emerging competition . By some estimates, the Arctic contains 30 percent of the world's undiscovered natural gas and 13 percent of its oil reserves. What's more, the receding ice could soon provide access to minerals, fish and other resources. At the same time, potential shipping routes — including the Northern Sea route and the Northwest Passage along the Russian and Canadian coasts, respectively — will become available, along with perhaps the Transpolar Passage in the more distant future.