A frozen peat bog in western Siberia the size of France and Germany put together contains about 500 billion tons of carbon. Western Siberia has warmed faster than almost anywhere else on the Earth, with an increase in average temperature of about 3C in the last 40 years.

Even more Siberian permafrost is under the ocean, an area six times the size of Germany containing about 540 billion tons of carbon. That submarine permafrost is perilously close to thawing. Three to 12 kilometers from the coast the sea sediment is just below freezing. The permafrost has grown porous, there is a loss of rigor in the frozen sea floor, and the surrounding seawater is highly oversaturated with solute methane.

“If the Siberian (submarine) permafrost-seal thaws completely and all the stored gas escapes, the methane content of the planet’s atmosphere would increase twelve fold. The result would be catastrophic global warming.” –”A Storehouse of Greenhouse Gases Is Opening in Siberia,” Spiegel, 17 April ‘08

There is a very inexpensive simple way to immediately cool the Earth: just put a small amount of aerosol into the air to dim the sun. We won’t be able to stop rapid ecosystem collapse without geoengineering. Soon melting permafrost will overwhelm any cuts we make to our emissions.

“The alternative (to geoengineering) is the acceptance of a massive natural cull of humanity and a return to an Earth that freely regulates itself but in the hot state.” –Dr James Lovelock, August 2008

They will then be able to form their own opinions on complexity and practicality.

I would be most grateful for help in identifying unfavourable side effects.

Like everyone working in geo-engineering I hope that the work will never be needed but fear that it might be needed with the greatest urgency.