@RC human knowledge is never certain but that doesn't mean there isn't a broad consensus that climate change is man made and likely very, very dangerous. As a father of three I'd be scared if there was just a 10% chance that we are on a slippery slope towards disaster and our odds are much worse then that.

A few times I have spoken to nuclear phycisists and I've always felt a little more at ease afterwards; whenever speaking to a scientist from the IPCC I am more worried. Just compare the most recent IPCC report (AR5) with the first one to see how consensus has shifted.