The National Oceanic and Atmospheric Administration released its annual Arctic report card last week, with data tracking seven vital signs of Arctic health, including air and water temperatures, sea ice and tundra greenness. The conclusion: “Arctic ecosystems and communities are increasingly at risk due to continued warming and declining sea ice.” In particular, there’s been a dramatic decline in older, thicker, more resilient sea ice. “Back in 1985, that kind of ice covered thirty three percent of the Arctic in spring,” said Don Petrovich, a professor in the Thayer School of Engineering at Dartmouth College. “Now, it's down to one percent of the Arctic ice cover.” To the extent that it’s being replaced, what is replacing it is younger, thinner, less resilient ice. That ice can’t survive major melting events. And when sea ice disappears, it reveals dark water beneath it. That water absorbs more heat than the reflective, white ice, kicking off a vicious feedback loop of warming and
The National Oceanic and Atmospheric Administration released its annual Arctic report card last week, with data tracking seven vital signs of Arctic health, including air and water temperatures, sea ice and tundra greenness. The conclusion: “Arctic ecosystems and communities are increasingly at risk due to continued warming and declining sea ice.” In particular, there’s been a dramatic decline in older, thicker, more resilient sea ice. “Back in 1985, that kind of ice covered thirty three percent