This article talks about the issue of climate feedback loops, and why they are one of the most troubling parts of global warming; they represent a worrisome unknown. Feedback loops are vicious, self-reinforcing circles that will speed up the pace of warming.
“For example, warmer temperatures make soil microbes more active. The microbes then release more carbon into the atmosphere – which in turn speeds up global warming, which makes the microbes even more active, and so on.
Melting sea ice is another example. Because ice is white, it reflects sunlight back to outer space, which reduces the heat absorbed by the earth. But global warming melts the ice, leaving dark ocean water behind. The water then absorbs the sun’s heat, which increases global warming … leading to more melting ice.