There is a book that is most illuminating: Atrocitology that I heartily recommend as a palliative to the ignorance meeted out by some climate change deniers. I won't use my own words when those of some commenters on WattsUpWithThat can do it for me nicely:
Really. Abundant evidence. That pair thinks so.
I did a Google search and beyond the fake conspiracy story that was Climategate, I can't turn up any real evidence. A day in court on the thin gruel that the deniers claim is abundant won't be a very long one. I can't see a judge, faced with one side of double spaced typing on A4, to spend too much time listening to arguments. It doesn't add up to so much as a bean, let alone a hill of them.
Yet this is something that the deniers like to state time and again. Here is James Delingpole having to defend himself against a similar accusation earlier this year when, to be fair, he only makes himself look foolish once again. It is easy to put up the accusation, much, much harder to provide any evidence. Which is why they don't, because there just isn't any.
On the other hand, the top ten atrocities committed by humans in history are listed here: I won't spoil it for you by revealing the number one but I am pretty certain you can work it out for yourself.
Anyway, there is a technical definition of crimes against humanity and the work of the Independent Panel on Climate Change is hardly likely ever to come close to meeting it. Even the Climategate fuss has been thoroughly debunked, trashed and shown up for what it was. A fuss over nothing. But deniers aren't bothered by the truth or such niceties as evidence. Otherwise there wouldn't be clips like these:
As for evidence that global warming is being caused by human induced changes to the atmosphere. Milondonharlani won't read this but go to skepticalscience. Linky on the right.
To sum up: crimes against humanity are serious matters. Real fraud is also a serious matter. The aim of the deniers is not to create a scientific case for their version of events, but to create doubt. If the public is persuaded to think perhaps there is something in this, then perhaps I shouldn't believe the science either. As Professor Iain Stewart says at the end of the Climate Wars clip (the second one), if you hear these sorts of charges, you know the scientific argument has been won. So little of the reason for climate science denial seems to rest on the actual science. It so often seems to rest on the "fear" of a new world government, a socialist conspiracy, extra taxes or something else that is neither science nor, very often, more than a fog of paranoia.