The global warming is not uniformly distributed over the Earth. The polar regions are especially sensitive for climate change and the warming in the Arctic is more than twice as fast as for the Earth on average. The effects of this warming are large, with a dramatic loss of sea ice as an example.

In the North Atlantic, a mighty current system conveys, via the Gulf Stream and North Atlantic Current, warm surface waters to northerly subpolar areas where deep water is formed. This current system, which is an important link in the global ocean circulation connecting the Atlantic and Pacific Oceans, also carries warm Atlantic water into the Arctic Ocean.