Getting to grips with a changing polar landscape.
The Arctic covers around 5% of the planet's surface, but it is capturing a disproportionate amount of attention. With temperatures rising at twice the global rate, the region's summer sea ice is shrinking rapidly, making access easier than ever before. At the same time, countries are racing to claim parts of the Arctic's sea floor and the vast deposits of hydrocarbons that lie beneath it.
Disappearing sea ice
Since satellite observations started in 1979, the September sea-ice extent has declined by 12% per decade, and the past 5 years have marked the lowest on record. The ice cover is thinning (see graph), making it more vulnerable to warmer temperatures. Forecasts by climate models (see graph) suggest that summer sea ice will largely disappear in the second half of the century, but the current rate of ice loss exceeds the models' forecasts, suggesting that ice-free conditions could arrive sooner.
Under the United Nations Convention on the Law of the Sea, countries can claim rights to seabed resources in the Arctic Ocean, depending on their coastline and the sea-floor geology. Dark shading on this map represents each nation's existing exclusive economic zone, which extends up to 370 kilometres from its coastline. Lighter shading depicts extended regions to which countries may be eligible. Russia and Norway are the only Arctic nations to have submitted their bids.
With its thick piles of sedimentary rock, the Arctic may hold some of Earth's biggest hydrocarbon stores. The high price of oil is driving companies northwards, with drilling taking place or planned off the coast of Greenland and in the Kara, Barents and Chukchi seas.
See After the ice, Nature's special on the changing face of the Arctic, for more.