SOURCE: Yahoo! Finance
DATE: April 22, 2019
SNIP: When the United Nations Intergovernmental Panel on Climate Change (IPCC) released its dire report in October warning of humanity’s fast-approaching reckoning with global warming, one factor adding to the urgency was a new estimate about how much additional carbon dioxide was being added to the atmosphere as a result of the warming of Arctic permafrost.
With rising Arctic temperatures setting free a vast amount of carbon previously locked beneath permafrost, the additional greenhouse gases released into the atmosphere would speed up warming, the report concluded — and that, in turn, would further melt the permafrost.
It is “feedback loops” like that one that make climate change unpredictable and represent a threat of global warming spiraling out of control.
“It’s already begun,” Thomas Crowther, professor in the Department of Environmental Systems Science of ETH Zurich, told Yahoo News. “The feedback is in process.”
Crowther estimates that carbon dioxide and methane emissions from thawing soils are “accelerating climate change about 12 to 15 percent at the moment,” and said past IPCC reports that left out the feedback “were way more optimistic than they should have been.”
Almost every scientist studying the effects of climate change is worried about the extent to which feedback loops will hasten global warming. One of the most serious concerns is the “albedo effect,” the amount of the sun’s radiation the planet reflects back into space, mostly from the polar ice sheets. The warming that has already occurred has begun melting the ice caps, leaving the relatively dark ocean and land exposed to absorb solar radiation — further warming the planet and leading to more ice melt.
“The impact that it has on making the earth darker by removing all the snow and ice is estimated by some to be 25 to 40 percent of the warming that we’ve experienced,” Jennifer Francis, senior scientist at the Woods Hole Research Center, told Yahoo News. “In other words, global warming is that much worse. There’s a lot of ways these things are totaled all together.”
Feedback loops are not a root cause of the climate change problem, but they make the problem that much worse. When climatologists began seriously studying global warming in the 1970s, there was some doubt about how the feedback loops would operate. Scientists theorized there might also be negative feedback loops, which would slow global warming — for instance, by increasing cloud cover. But so far it has all gone in the opposite — wrong — direction.