February 15, 2009 More from Fields Below – Astonishing news about Permafrost Catastrophic permafrost melt is one of the likely abrupt climate change feedback scenarios. Major permafrost melt has already happened and the melt rate is increasing rapidly. Hundreds of thousands of years of frozen, partially decomposed tundra is at risk of thawing. Scientists aren’t sure yet how rapidly the thaw will take place, but they know that the rate will likely increase over what it is now and it could increase very dramatically.
The new estimate of the total amount of carbon frozen in permafrost soils was about 1000 billion tons. The amount of CO2 released through burning fossil fuels since the beginning of the Industrial Revolution more than 200 years ago is about 350 billion tons.
Future (as well as current) forest fires may also play a leading role in CO2 feedbacks. The Equatorial rainforests are of most concern. As the climate warms, jungles dry out. At some point they get dry enough to burn.