A physicist has put up $30,000 of his own money to challenge global-warming skeptics to unequivocally show him evidence that man-made global warming doesn't exist.
Dr Keating -- a professor of physics for over 20 years and author of Undeniable: Dialogues on Global Warming -- is offering a grand prize of $30,000 of his own money to anyone who, using the scientific method, can disprove the existence of man-made climate change. In addition, he is offering a smaller prize of $1000 to anyone who can provide any valid scientific evidence against man-made climate change.
You can read his official statement of the challenge on Keating's blog.
Now, this is NOT to say that he is looking for proof of warming due to anthropic causes. There's a difference here. He's looking for FALSIFICATION of the claim, i.e. evidence that such a claim of human origins for global warming isn't valid.
Also note that he is not a fly-by-night physicist moonlighting as a climate expert. So you'd better be good at this, because he is!