All around the world, oil and gas companies are being forced by resource declines to drill in less accessible areas, and the Arctic is their newest frontier. The geology above the Arctic Circle—that is, everything above latitude 66.56°N—holds an estimated 90 billion barrels of oil and 1,669 trillion cubic feet of natural gas, or 22% of the world’s undiscovered conventional resources, according to the U.S. Energy Information Administration.