I'd be fine believing all those dire prognostications if they had skin in the game. I.e. you're a climate scientist, you say "science is settled", and you project that in 20 years something concrete and catastrophic will happen and it does not (which BTW, historically it usually doesn't), you go and spend a few years in jail. That'd tone down the rhetoric considerably and bring it back into the factual realm where we can actually work on concrete solutions to issues.
Right now, though, there's every incentive for predicting doom and gloom and no downside at all (in fact you could be kicked out of the profession if you don't do it), so half the country believes we're all going to be dead in 12 years because cows fart. You're not going to get meaningful policy out of this. You can get a binary, extreme choice instead: if the "greens" prevail we shut down our economy and that does nothing anyway because everybody else burns coal. If they do not, everything continues down the same path it's been going for the last 100 years, and in another 30-50 years we'll start to really feel it, but by then it'll already be way too late, barring some dramatic technological breakthrough in atmospheric carbon capture (and energy generation which will be required to power carbon capture).
The only way out at the moment seems to be in nuclear, but that's not happening either, which indirectly tells me that the situation is not as fatal as the prognosticators imply. Because if it was, really, unequivocally a matter of survival, we'd be launching a nuclear reactor a month from here on out, and encouraging others to do the same. Not to mention Barack Obama (who should be more reliably informed than any of us here) would not buy that beachfront property on Martha's Vineyard.
