rapid freeze - sudden climate changes , page-12

To all the AGW nay-sayers, this is no spanner in the works!

"There is some speculation that global warming could, via a shutdown or slowdown of the thermohaline circulation, trigger localized cooling in the North Atlantic and lead to cooling, or lesser warming, in that region." [Wikipedia]

To explain briefly the way this theory works - melting of ice sheets and glaciers could cause a massive influx of fresh water into the region, which is less dense than salt water. The Gulf stream or thermohaline circulation requires the more dense, cool and salty water to sink to keep the circulation going. There is speculation that the less dense fresh water could interrupt the thermohaline circulation thereby slowing down or possibly even shutting down the Gulf Stream leading to cooler temperatures in north western Europe. All very logical but it is just a theory. From the article above it looks like it may have happened in the past.

More information here:

http://en.wikipedia.org/wiki/Shutdown_of_thermohaline_circulation

And here:

http://en.wikipedia.org/wiki/Thermohaline_circulation