The following link has a review of David Archer's book on global warming/climate change, "The Long Thaw". I include some of the review concerning how long the effects of our actions can be expected to last, to augment the previous post based on a technical study, to which David Archer contributed research.http://hubpages.com/hub/The-Long-Thaw-A-Review
I suggest reading the whole review, which is itself well-written and informative.
David Archer’s The Long Thaw may just have the best symbolic cover graphic of any recent book on climate change: a human fingerprint, 90% submerged in true iceberg fashion, beneath a cloudy sky. One scarcely needs the subtitle—How Humans Are Changing The Next 100,000 Years Of Earth’s Climate.
Archer, an oceanographer and professor of geophysical sciences at the University of Chicago, is a master of the “Plain Style”—informal, and given as much to the simple declarative sentence as to the factual.
Chapter 10 considers the possibilities for future carbon cycle feedbacks. Currently, the carbon cycle is damping human-induced climate changes, but there are ways in which this could change. In past climate changes, warming temperatures produced increased CO2 concentrations in the atmosphere, unlike today, when humans release CO2 which is partially absorbed by plants and by seawater.
But CO2 release in response to warming could easily happen again, if any of the things acting today as carbon sinks--the oceans, for instance, or the great boreal forests--begin instead to emit CO2 as they warm. For instance, the ocean waters grow less able to hold CO2 as temperatures warm. Permafrost can melt, releasing CO2 or methane, and the massive amounts of methane held as hydrates buried in oceanic sediments could melt and bubble up through the water column to enter the atmosphere.
It is not possible to predict which, if any, of these things will happen, or when. But if they do, it is possible that the warming effect of CO2 could quickly double.