The first is caused chiefly by sun activity, cyclical changes and other factors, while the latter is about "man causing it". There is no doubt that there are warming trends (and cooling phases) throughout earth's history.
Many Conservatives who are quoted as anti-Global Warming voices expressedly are skeptical of "man made Global Warming", not "Global Warming" per se.
Governor Palin repeatedly has said that she is skeptical of man's role in it and that it is not a determing concern for her energy policies.
Those saying there are NO climate changes are wrong.
There are changes, but there is no conclusive proof that it is caused by man.
I would advise all FReepers use the following when starting out in any conversation with others about this...
“I don’t believe in Anthropogenic Global Warming, although I do believe in Global Warming...”
And I would use the word “anthropogenic” in saying that, because it will get people (most of the time) to ask you what that is...
Then, I would *start out* by saying that it’s a proven scientific fact that there is global warming, but also there is global cooling. And then I would go into the AGW... :-)
And, definitely, don’t forget to have that documentary with you, too... LOL..