Reply #24: Maybe, but it's highly unlikely - there are natural positive feedback loops in place

[hatrack]

Example - As the polar caps, particularly in the Arctic shrink, more of the ocean (as opposed to ice) becomes exposed to the sun. Since dark matter like seawater absorbs far more infrared radiation than a light reflective surface like snow and ice, the region absorbs still more solar inputs, melting even more ice, and exposing even more seawater, and so on.

Example - Permafrost and frozen bog soils across Canada, Siberia and Alaska are melting down. These soils contain large amounts of organic matter which have been out of the carbon cycle for thousands and thousands of years. Now, as the soils warm, bacterial action starts back up again, releasing more carbon dioxide from previously frozen soil. Also, the same process releases large quantities of methane, another greenhouse gas with about 25X CO2's capacity to trap infrared radiation. The West Siberian peat bog alone contains about 70 billion tons of methane, which is the equivalent of about 2 trillion tons of CO2. Not all of it will necessarily be released, but the more that is released, the more that will be released.

Example - methane ices (a.k.a. clathrates) - this is a form of methane trapped in ice crystals and buried in ocean sediments around the world. It's estimated that there are about 10,000 billion tons of the stuff. No one knows under just what circumstances a methane ice release might take place, but it would likely involve a rapid warming which destabilized the water ice in which it is trapped. Now, a new report indicates that methane ices are much closer to the surface than previously thought - as shallow as 60 to 100 meters beneath the sea floor, which would make a temperature-related destabilization perhaps somewhat more likely than thought.

And in each of these cases, the physical scale is so huge that it makes human intervention unlikely to have any substantive effect.

So, "roll back" climate breakdown? Probably not. Slow the warming? Certainly!

From New Scientist on Methane Release:

THE world's largest frozen peat bog is melting. An area stretching for a million square kilometres across the permafrost of western Siberia is turning into a mass of shallow lakes as the ground melts, according to Russian researchers just back from the region.

The sudden melting of a bog the size of France and Germany combined could unleash billions of tonnes of methane, a potent greenhouse gas, into the atmosphere.

The news of the dramatic transformation of one of the world's least visited landscapes comes from Sergei Kirpotin, a botanist at Tomsk State University, Russia, and Judith Marquand at the University of Oxford.

Kirpotin describes an "ecological landslide that is probably irreversible and is undoubtedly connected to climatic warming". He says that the entire western Siberian sub-Arctic region has begun to melt, and this "has all happened in the last three or four years".

EDIT

http://www.newscientist.com/article.ns?id=mg18725124.500

From BBC on methane ices:

Scientists drilling ocean sediments off Canada have discovered methane ices at much shallower depths than expected. The finding has important implications for climate studies, they believe. The melting of hydrates, as they are known, is a suspected contributor to past and present increases in atmospheric methane, a greenhouse gas.

If shallow ices are destabilised in a warming world, it could have a positive feedback effect and drive temperatures even higher, the researchers warned.

"The rate of increase in the Earth's atmosphere for methane is much faster than that for carbon dioxide," said Timothy Collett, the co-chief scientist of the Integrated Ocean Drilling Program (IODP).

"Methane is 20 times more effective as a greenhouse gas than CO2. The source of this methane is uncertain, but there are a number of scientists who have looked at gas hydrates as contributing to this recent change."

EDIT

http://news.bbc.co.uk/2/hi/science/nature/6166011.stm