Maximum sea ice in the Arctic is shrinking more rapidly than before. Satellites showed an average shrinkage of 1.5% per decade since 1979, but for this year and last, it is now 6% per year.
There’s still a fair amount of ice left, about double the size of the United States. But this will change; already the melt season is two weeks longer. Oceans absorb more than 95% of light, while ice reflects some 80 – 90%, the water around and under the sea ice warms, and the melt rate speeds up.
This process will not increase sea level (melt ice in a full glass of water and check for spills), but will freshen the water. Concerns about shutting down the currents due to a large increase in fresh water center on the much greater impacts of rapid melting of Greenland’s glaciers. However, marine animals are being badly hit:
According to [Joey] Comiso [a research scientist at NASA’s Goddard Space Flight Center], if the winter ice retreat continues, the effect could be very profound, especially for marine animals. “The seasonal ice regions in the Arctic are among the most biologically productive regions in the world,” he said. “Some of the richest fisheries are found in the region, in part because of sea ice. Sea ice provides melt-water in spring that floats because of low density. This melt-water layer is considered by biologists as the ideal layer for phytoplankton growth because it does not sink, and there is plenty of sunlight reaching it to enable photosynthesis. Plankton are at the bottom of the food web. If their concentration goes down, animals at all tropics level would be deprived of a basic source of food.”
