Arctic Sea Ice is melting much, much faster than even the best climate models had projected. The reason is most likely unmodeled amplifying feedbacks. Image via Arctic Sea Ice Blog.
We’ve known for a long time about basic polar amplification. Warming melts highly reflective white ice and snow, which is replaced by the dark blue sea or dark land, both of which absorb far more sunlight and hence far more solar energy.
More recently another insidious feedback has become obvious — as the Arctic ice retreats, big oil companies can drill for more fossil fuels whose combustion will accelerate warming and ice retreat. You might call this the “brainless frog” feedback.
Now Reuters reports on yet another feedback:
Local pollution in the Arctic from shipping and oil and gas industries, which have expanded in the region due to a thawing of sea ice caused by global warming, could further accelerate that thaw, experts say.
The United Nations Environment Program (UNEP) said there was an urgent need to calculate risks of local pollutants such as soot, or “black carbon”, in the Arctic. Soot darkens ice, making it soak up more of the sun’s heat and quickening a melt….