I disagree with your comments on the IPCC, okay they may have made some mistakes, but there is absolutely no incentive for them to lie about climate change, they are an independent commitee, not funded directly by governments, but through UN funding. Im sure there are other people linked to oil companies and such who would love to see climate change squashed though...
As for those mentioning the change from global warming to climate change, this is because not everywhere is going to get warmer, but temperatures over a global average will rise.
The key evidence I see as being that global temperatures are linked to CO2 levels in the atmosphere, and since the industrial revolution there has been a signficant increase in the levels of CO2 as a result of our activities. Im not doubting that there are also natural reasons for a CO2 increase either, although some of this could also have resulted from feedback systems like silvergirl mentioned with the likes of increased forest fires and CO2 being released from melting permafrost. But with this rapid an steady increase in CO2, all indication is that the global temperatures will follow.
No one has also mentioned that we have to be aware of the possibility of a tipping point where feedback systems will take over and the effects become irreversible.
And for all those against the likes of green taxes. Okay they do make governments a bit of money, but how many people now look for more economical cars because of the price of fuel? Fuel economies for cars have almost doubled in my life time... I bet that wouldn't of happened if there weren't the taxes. It can be proved that wouldn't of happened even, just by looking at the yanks.
I say all this but I know I don't understand it all fully, I am just an A level geography student. What I will say though, is that I would rather listen to accredited scientific journals than some random videos that an unknown person uploaded onto the internet.
Edit: Oh and the water vapour only stays in the atmosphere for short amounts of time, CO2 for a hell of a lot longer.