Science: Climategate and questions I would want to have answered

Yes, Drudge can add sensationalized headlines to items and highlight odd stories.

But most of the time, he just links to articles that he thinks are interesting.

And so he links to an item that says Al Gore was confused on the emails regarding the "Climategate" scandal.

From that item, there are links to various web pages that highlight why some people are skeptical of man-caused global warming.

The daisy-chain as Dennis Prager points out is as follows:
(1) human activity produces CO2
(2) there are temperature increases
(3) CO2 increases lead to temperature increases
(4) temperature increases will result in calamity.

This is what I would want to know:
Statement #1 is probably true. But in the history of the planet has there been times when CO2 were higher than the are today which would have occurred without human activity?

Is statement #2 actually true? Modern technology gives us good temperature data from many locations. But that is using current technology. How good is the data when you go back into history? How do you figure out the temperature when nobody was sitting around with thermometers to measure it?

Is statement #3 actually true? In science there is causation and correlation. Is CO2 the cause of temperature increases? Or are temperature increases the cause of CO2 increases? Or is there some other factor driving the temperature like solar activity?

Statement #4 would be true if we get many degrees of increase in temperature. In the past, there have been ice ages when temperatures dropped which would be bad too! And in the past, there have been much warmer temperatures. So the question is, how many degrees will the temperatures rise, if indeed they are rising? There is a huge difference between global warming of 1 degree C versus 6 degree C.

I'd also want to know why man-made global warming advocates dismiss skeptics by saying they make money from energy companies (I'm sure some do but probably don't) when it could be said that global warming researchers make money from grants studying global warming?

This last question is rhetorical but the previous ones are real questions I'd have about the science of climate change.

UPDATE: Prager rounds up latest problems with global warming in regards to Himalayan glaciers melting.