I wrote the following in the context of another blog conversation (note that here I've both edited that langage as well as added to it):
(A) Is the Earth experiencing climate change (I really do not like the term "global warming")?
Yes. But that is hardly surprising given the history of this planet's climate.
(B) Is the change rapid in nature?
Probably no more rapid than some periods in the planet's history. How rapid were the were the changes in the past that occurred with the greatest alacrity and what did these changes add up to re: overall climate, etc.?
(C) Is it at least in part a result of man-made processes?
Probably. Though there are also likely other factors involved.
(D) What future problems (or benefits) can we expect from these changes?
This is where scientists seem to be all over the map.