Environment

Arctic sea ice is shrinking at a rate much faster than scientists ever predicted and its collapse, due to global warming, may well cause extreme weather this winter in North America and Europe.Decades ago, Arctic ice covered about 6 million square miles of sea in the winter, and would shrink to about 3 million square miles in the summer. The rate of summer melt increased enormously around 2005, however, and today scientists say Arctic ice covers only about 1 million square miles.

The loss of Arctic ice has several effects. Ice reflects heat and solar energy back into space. With less ice cover, that heat energy is instead absorbed by the ocean, which warms and melts more ice. Currently, the Arctic region is the fastest-warming region on the planet, and the change in temperature will probably influence weather patterns here and in Europe.

The heating and cooling of Arctic seawater has been affecting the jet stream – the river of air that flows from west to east high above the Earth’s surface – and has slowed it down, Francis said. The jet stream controls the formation and movement of storm systems, so when its movement slows, weather conditions persist for longer periods of time over the same area. They get “stuck.”