Lots and lots of people have been going through the CRU material mentioned before.
Here’s a rather extensive analysis by Marc Sheppard over at American Thinker as to why the “nothing to see here” line on the various hacks and tricks mentioned therein don’t hold water. if I’m reading it correctly, and the analysis is correct, then at least half of the 20th century warming trend (and all after about 1998) are the results not of solid science, but of various hacks to skew the data.
By all means, let’s get better data on the climate. But we’d be insane to cripple our economy through meaningless treaties like Kyoto and Copenhagen based on blatantly manipulated data pushed by people with a post-national agenda of higher taxes, bigger government, and control of vast swatches of the world economy by unelected international bureaucratic elites.