Here's Richard Lindzen's talk at the Heartland Institute conference earlier this month. It's well-worth listening to.
His scientific arguments (as presented here) are very high-level and there's really not much you can say about them. But I do think one of his ideas is worth thinking about: if you really do not accept the AGW statements given by the various scientific societies, quit your membership with that society. Perhaps you should even go and form your own society. That would be a much more useful statement than signing some petition with thousands of essentially untraceable names which lack institutional affiliations, addresses, etc., which has also been signed by Ginger Spice.