The climate IS changing, that much is clear. But (and it's a big butt, hee-hee) we don't know a couple of variables:
1) is this 'normal' for the planet? We know there have been periods with more cold as well as more heat than now. 2) Is it man-made? Could very well be, but is taxing the problem to reverse the effects? Hell no. Not as long as big oil companies can influence lawmakers in order to push their agenda. We could have had thorium-reactors, vastly more efficient solar-panels, highly effective wind-turbines and hydrogen-engines for years, if it would not have been for major players who have wayyy too much to lose from clean energy. 3) What's the deal with the claim it's not just Earth that's heating up, but the other planets in our solarsystem as well? Heard about this a couple of months ago and I haven't had the time to dive into it with more depth. Apparently as long as there's money to be made from the destruction of nature, we're like the dinosaurs but with the only difference we DO see the asteroid coming. We just think it's someone else's responsability to do anything about it.
I think it's been pretty much established with the extent of temperature data that we have that were our emissions controlled we wouldn't be seeing global warming on the particular scale that we're seeing it for quite a long time, if we were even eventually going to witness it. It's not just big oil companies, who seem to be making investments quietly in renewable energy to keep themselves afloat as oil runs out. It's their employees - geologists, for one, may be on the other side of this debate, as a lot of them are employed by big oil.