The wait until the car drives off the cliff before thinking about putting on the brakes theorem .
See, it's this kind of "we've got to do *something* now!" thinking that's so destructive to rational thought. If the proposed "fixes" for climate change were minor and otherwise insignificant then nobody would mind. But they are not. The proposed changes will be costly, both in terms of real money and in terms of people's quality of lives. If you want someone to make a drastic change in their lives, you need drastically good evidence. Thus far, you have *some* evidence, but that does not equate to proof.
First, is the planet getting warmer? On that I'd say there's general agreement, although it is not a 100% consensus.
Second, if it is getting warmer, is it caused in large part by human activity or is it part of some natural variation? This is the sticking point. If it's part of a natural variation in temperature -- and I will point out many such variations have happened in the past few million years, all without any input from humans -- then there is no need for us to radically alter our life to stop it because such actions will have no positive climatic effect while having a signficant negative effect on quality of life.
Third, if it is anthropogenic, what should we do about it? Curtainling greenhouse emissions is an obvious choice, but is it the best one? How severe are the predicted warming effects? The economic and socio-political upheavals from drastic policy changes might be worse than adapting to a changing climate. And how much confidence can we have in the predictions regardless of how severe (or not) they may be?
These are not minor issues. They deserve to be studied and debated *in depth* before drastic action is take, if for no other reason than to determine that we're taking the *most effective* action possible. This whole "the debate is settle and if you don't agree with us you're a denier" smacks of the same kind of thinking that gave us an Earth-centric cosmic model and burned "deniers" as heretics.