I've republished this post because of the good comments someone has made.
ScienceDaily (Feb. 7, 2011) — The substantial decline of Arctic sea ice in recent years has triggered some fears that the ice cover might be approaching a "tipping point" beyond which the loss of the remaining sea ice would become unstoppable. However, new research carried out at the Max Planck Institute for Meteorology in Hamburg/Germany now indicates that such tipping point is unlikely to exist for the loss of Arctic summer sea ice. The sea-ice cover reacts instead relatively directly to the climatic conditions at any given time. Hence, the ongoing loss of Arctic sea ice could be slowed down and eventually stopped if global warming were to be slowed down and eventually stopped.
There are some good comments for this post. I have tried to change my blog so that comments appear in-line, but I think I would have to go thru a conversion process which I haven't had time to do.