Why the debate?
1) Politicians love to give us all a new Bogeyman, and to raise any new tax that they can. It's a given. They're a bunch of evil thieving manipulative swine, granted.
2) The scientific community says they're over 90% sure that we're looking at a 2-5 degree rise this century, largely caused by greenhouse gases.
What's the problem? These two things above are perfectly compatible.
Polticians do indeed pressure the IPCC to word things so that the worst possible spin is put on things. They might even try to increase funding to doubters. But overall the scientific community remains massively independent and its voice is still spectacularly clear on this. They incorporate all the doubts, put a percentage certainty on their conclusions, and stake their reputations on their reasoning. So either
(1) the thousands of scientists involved in climate research are all part of the greatest conspiracy / cover-up of all time;
(2) or there's some flaw in their data (or models, or logic, or use of models) -- and despite it being precisely their job as scientists, they're uniformly too stupid to see it, but you, the Denier, are not;
(3) or the conclusions they provide do indeed represent the best reasoning humanity has (which is what we pay scientists for).
For (3) to be true, could the Deniers then just largely be people who haven't realised that the Politicians / Bogeyman / Tax angle isn't incompatible? So they latch onto any item of apparent counter-information that they see in print, no matter how unfortunate its provenance, calling it "yet more evidence". (An entirely understandable thing to do, given that the biggest driver of the human thought process is the subconscious desire not to be proved wrong. And especially easy to continue with, when it may take half a lifetime to find out.)
Deniers, you are of course absolutely right about the Politicians / BoogieMan / Tax angle. But do have another think about the Scientists being all either corrupt, or part of an enormous political cover-up, or less logical than you. Far, far more likely is that they're right too.