Where can one find hard data supporting human-caused climate change?

I admit I am skeptical about man's activities affecting climate, mainly because no one ever presents data. What I see most of all are statements saying this group of scientists believe, or this UN group believes. Sometimes you might see "carbon has increased in the last century due to man's activity, and this is causing warming". Where is the data?? My understanding is that this hypothesis (some say fact) is based on computer models. I am not a scientist, nor do I construct simulations, but I know a good deal about the modeling of complex systems from the industry in which I spent 15 years. I saw a model described in Scientific American 5-6 years ago that was pathetic. Where is the data that will tell me precisely how much of climate change is caused by man, precisely how much is caused by sun spot activity, how much is caused by the earths wobble on its axis, volcanic activity, methane introduced by fauna, etc. Unless the discrete effect of each of these causes can be stated with an extremely high degree of precision, a model that will predict future change with even 25% accuracy cannot be constructed. Show me the data - or tell me where I can find it. Also - any fact or opinion promulgated by any part of the United Nations cannot be considered reliable in any way, so don't waste my time with anything from them.