Arctic Circle level, although in mountainous regions there is often no direct view of the true horizon. Only four million people live north of the Arctic Circle due to the severe climate; nonetheless, some areas have been settled for thousands of years by indigenous peoples, who today make up 10% of the region's population. Tens of thousands of years ago, waves of people migrated from eastern Siberia across the Bering Strait into North America to settle. The largest communities north of the Arctic Circle are situated in Russia, Norway and Sweden: Murmansk (population 307,257), Norilsk (175,365), Tromsø (71,295), Vorkuta (59,231) and Kiruna
Natural resources of the Arctic BTOE of energy, 31% from oil and 21% from natural gas). Russia’s vast energy resources account for 52% of the Arctic totals and Norway’s for 12%. Norway, which has been extracting petroleum in the North Sea since the 1970s, in the 2010s expected new discoveries in the Barents Sea. As of 2013 Russia was exporting 88% of crude oil via pipelines, with a large majority of the natural gas also transported in that manner. 76% percent of natural gas and 79% of oil were exported to Europe, with the second largest customer for oil being China and for natural gas