There is a problem with the last remaining remnants of the Arctic ice cap. It could all just float away someday. This first became evident about ten years ago when the ice broke loose from Severnaya Zemlya, islands along the Asian coast. Previously, the ice had always been fixed to land at at least three points. The resulting triangulation, on the same principle that keeps buildings standing up, had prevented large-scale movement in any direction. In the summers since, Arctic ice has been attached only at Greenland and Canada, on the North American side of the ocean.
But this month the ice has broken free from North America too. The crack separating the main ice pack from the coastline is up to ten kilometers wide and easy to find in the satellite pictures. Not tethered anywhere, the ice is free to drift off in any direction, to sunnier climates and warmer water where it can melt away. It is only by luck that this summer is the first summer in ages in which there has been barely a breeze across the Arctic Ocean, so the ice is still relatively in place.
This luck will not hold for long, of course. Any change in the weather will push the ice in some direction, and change is on the way. The weather forecasts hint at a persistent high pressure system, reaching north into the Pacific side of the Arctic Ocean with warm air and winds. The details of winds are harder to predict, but any movement at all will melt some of the ice involved. Someday, probably not this summer, a storm will push most of the strongest ice out of the central Arctic, probably either into the Atlantic or in the opposite direction, toward the Pacific. If that were to happen in April or May, there could be no sea ice left in the Northern Hemisphere by August.
