Currently available shipping lanes through the Arctic in September. The fastest navigation routes for ships seeking to cross the Arctic Ocean during September currently favor the Northern Sea Route along Russia’s coastline. Red lines indicate the fastest available trans-Arctic routes for Polar Class 6 ships (moderate-capability icebreakers such as those used today in the Baltic) between the North Atlantic and Pacific oceans. Blue lines indicate the fastest available routes for common open-water ships. Where overlap occurs, line weights indicate the number of successful transits following the same route. Dashed lines reflect currently existing offshore sovereignty boundaries. A white backdrop indicates sea ice concentration. (Image courtesy of Proceedings of the National Academy of Sciences) (Click image to enlarge)