North Pole meltdown

The cryosphere comprises the areas of the Earth's surface containing water in solid form, including snow, frozen ground, sea ice, glaciers and ice sheets. The two most important components of the cryosphere are the north and south polar regions - the Arctic and Antarctica. The Arctic region is a polar sea of pack ice surrounded by land; Antarctica is a polar continental ice sheet surrounded by sea. Historically, both the northern ice pack and the southern ice sheet occupied roughly the same areal extent of 16 million square kilometres.