Polar ice caps gone by 2060

The extent of polar ice is as low as it has been since satellite images first became available in 1978. At the current rate of decline, the polar ice caps will be gone by summer 2060.

But there are good reasons to believe the decline will accelerate. Polar ice is white; it reflects sunlight into space. Liquid ocean water, by contrast, is dark; it absorbs the light and converts it to heat, warming the water and melting more ice. Other positive feedbacks will kick in later. Melting permafrost will release frozen methane, which will work as a greenhouse gas, further accelerating global warming. NY Times:

“Feedbacks in the system are starting to take hold,” Dr. Scambos said. “The consecutive record-low extents make it pretty certain a long-term decline is underway.”

Read more: BBC News, NY Times