See the problem here is that your assuming the AGW crowd isn't the Roman Cathoilic Church! Maybe they are right, a lot of evidence appears to say so, but these are complex systems with lots of inputs and can swing wildly for many reasons. After all we had the global cooling warnings in the 1970s who many people were absolutely convinced were right. We have also had wildly inaccurate predictions (sensationalism) from the AGW crowd and clear attempts to hide data manipulation.
But the clear problem is just saying people are in "denial" is just like a kid taking his toys and going home. All that we assume to be correct is up for debate, you can choose to debate or not, but trying to stifle debate is wrong and dangerous. we have the crap where we want to stifle debate by prosecuting those that question AGW. Really? That really sounds like a church demanding adherence to the teachings. Then you have that the IPCC says their predictions are 66% likely to be accurate, that's a pretty big uncertainty.
Next we come to what can really be done. If I said we need to make a 4% reduction every year, would that make AGW fanatics happy. Well if you think the peak oil depletion numbers are accurate, then that's what's going to happen if we do absolutely nothing at all.
I wasn't criticizing him of his ardent support for AGW, he is free to believe and act as he see's fit, which he appears to do. I was criticizing the belief that he is absolutely correct and in much the same way you do above, and believe anyone who doesn't agree is wrong. Maybe, maybe not. There is a lot more uncertainty in these complex systems and when you start to act like a religion that must squash all dissent, that is a problem.
Then we come to the issue of if you "force" your beliefs onto others, it generally doesn't work anyway and often has the opposite outcome. When people are forced into situations instead of voluntarily accepting things, you get resentment and push back. My recommendation is stop with all the "strong" arm tactics such as carbon taxes (which are just disguised force) and do education, set examples and encourage change voluntarily.