'Four degrees and beyond: the potential for a global temperature increase of four degrees and its implications'

Philosophical Transactions of the Royal Society, the oldest continuously published scientific journal in the world, has published a theme issue on global warming that is available free through Thursday. Short version: we're fucked.

The Guardian summarizes:

A hellish vision of a world warmed by 4C within a lifetime has been set out by an international team of scientists, who say the agonisingly slow progress of the global climate change talks that restart in Mexico today makes the so-called safe limit of 2C impossible to keep. A 4C rise in the planet's temperature would see severe droughts across the world and millions of migrants seeking refuge as their food supplies collapse.

I've been debating global warming in the comments section of a minor conservative blog for a several years now, not because I'm a masochist but just to see how the other side thinks. For the first few years they denied that there was a consensus on global warming at all although the latest studies show the consensus among climate scientists at about 97%. Now they argue that the consensus is wrong although it is never clear how they know this, except that it is obvious to them that AGW is a plot of some kind. I bring up the Royal Society or the National Academy of Sciences; they link to some obscure Exxon-paid hacks who publish in nonscientific publications, in one case a LaRouche magazine. I concede that it is remotely possible that the 3% could be right, despite the overwhelming nature of the consensus, despite the links to Exxon on the part of many of the skeptics, despite the fact that they never seem to do any actual research or publish in peer-reviewed journals. Still, it is within the realm of possibility, however unlikely, that they are right. My conservative debating opponents are 100% certain however that they are right and I am wrong. One of them also doubts the "consensus" on the theory of evolution. Like the evolution deniers they ask for one "proof" that C02 is causing the increase in temperature, when they are not denying that the Earth is warming at all.

One week they deny that there is a consensus, another week they argue that the consensus is wrong. One week they deny the earth is warming, it is actually cooling they say, another week they argue that the whole solar system is warming due to natural causes, based on misinterpretations of some climate data for Mars. In the end they call me an idiot and close the comments.

My opponents are not even the nuttiest of the wingnuts. They are not birthers for example. But their minds are made up. So is mine I suppose but I concede the possibility that I could be wrong. I am not a scientist. I ask myself, if I were President what would I do? Study climatology in my spare time, work toward a Ph.D. and then review all the scientific literature? Or be guided by the considered opinion of the National Academy of Sciences and 97% of the experts in the field. That's what their idol Reagan did regarding the hole in the ozone layer, although I believe my opponents also still dispute the ozone connection. The mythical Reagan is their God but the real Reagan would be considered a moderate by their standards.

Although they believe that they are right on the Science lately they have been pointing out that they are winning on the Politics, that the Skeptics have succeeded in preventing anything serious from being done about global warming. Here they may very well be right making the worst case scenarios of the Royal Society all the more likely.