Vicious Global Warming Feedback Loop Worse Than Feared
Vicious cycle: amount of warming involved in Arctic ice loss, now amounts to roughly one-quarter of all warming
- Jacob Chamberlain, staff writer
19 February, 2014
One of nature's key defenses against global warming—the reflection of the sun's rays away from Earth by Arctic sea ice—has fallen victim to... global warming. And according to a study published Monday, the vicious feedback loop is worse than previously thought.
The Arctic sea ice retreat has been one of the most dramatic climate changes in recent decades. Nearly 50 years ago it was predicted that a darkening of the Arctic associated with disappearing ice would be a consequence of global warming. Using satellite measurements, this analysis directly quantifies how much the Arctic as viewed from space has darkened in response to the recent sea ice retreat. We find that this decline has caused 6.4 ± 0.9 W/m2 of radiative heating since 1979, considerably larger than expectations from models and recent less direct estimates. Averaged globally, this albedo change is equivalent to 25% of the direct forcing from CO2 during the past 30 years.