I would say it\'s a hypothesis I have read about before - I belive ice core analysis showed that a temperature change of about only 4 degrees celcius caused the last ice age and over the past hundred years the global temperature has changed a bit more than 3 degrees. [EDIT, sorry a bit over 2 degrees I believe]
Could you elaborate on the global mechanism?
I have heard a very sound hypothesis, that is being studied right now, that suggests that Global Warming will cause Europe to become much, much cooler - this has to do with the ocean conveyor belt - warm, less saline water runs from the bottom of the African continent up around Europe, and this warm water carries a huge amount of energy from the tropics northward - that\'s why Rome is at the same latitude as Chicago but is much hotter. Once the water nears the coast of Greenland, it meets dense, salty water from the arctic ocean, sinks and goes back down to the tropics and the cycle continues. The hypothesis suggests that as the polar arctic ice-caps continue to melt as they have been doing, they will continue to release FRESH (ie non-saline) water off the coast off greenland - this will disrutp the conveyor belt, because the water needs to be salty (and therefore dense) to drop down and drive the oceanic converyor belt. Therefore, the entire belt will \'shut down\' and Europe will become as cold as similar latitudes in the US - so you\'d see snow in Rome, and London would be blizzard central.
I\'ve only read of the theory, and not of any major findings so I can\'t comment of the validity - except for the fact that the oceanic conveyor belt described DOES exist.
