As for sudden climate change: that is a real bogeyman for the deniers. I work with some of the key people who came up with the evidence for sudden climate change and just about 3 days ago saw one of them present the record of huge changes in a couple decades: huge warmings. The earth can switch from state A to state B....
I don't know how likely that would be this century, and that would be an interesting topic of conversation here, but it seems real real clear that it has happened in the past.
Chris

Chris, no one doubts Global climate changes, even sudden global climate changes. I think the big debate is how much influence on the works is the Human, or how much control we can possibly have.

Clearly you are saying there have been sudden changes in the past - were those prior to the last 300 years? I would assume so - and what caused those changes? What's to say these climate changes aren't the natural occurring cycle? We all know ice ages come and go... and we're coming out of the last one just 10-12,000 years ago. But we know that we are on opposite sides of the fence on this question.. Only time will tell the real story.

I think, as humans, we need to think we can control our environment.. that is clearly impossible.

Canie