Until very recently there were two huge roadblocks in the way of any kind of global deal on climate: China’s soaring consumption of coal, and the implacable opposition of America’s Republican Party. The first seemed to mean that global greenhouse emissions would rise inexorably no matter what wealthy countries did, while the second meant that the biggest of those wealthy countries was unable to make credible promises, and hence unable to lead.
Krugman never misses a chance to ding either of these favorite nemeses of his (China and the Republicans), although in the case of China, Krugman's peculiar singling out of coal as a culprit has always seemed a little off. "Coal" is not a heat-trapping greenhouse gas. It's a dirty pollutant, but we should not forget that China has 1.2 billion people and is responsible for 26% of all GG emissions, whereas the United States has 300 million people (5% of the world's population) yet manages to belch out 16% of all emissions. I think this is part of Krugman's idiosyncratic belief that the solution to global warming is to eliminate all use of coal and "reduce somewhat" other fossil fuels. I'm not sure, as I've said before, where he got this formulation, although I suspect that he wonders how well his career (or legacy, at this point) as a Keynesian "growth" economist will do in an age of steady-state economics.
As to the second hurdle, the Idiot Caucus in the U.S. Congress, we may as well face it: nothing is going to change that, and "executive action" will never be enough. The "leadership gap" that Krugman laments is part of a New York Times conceit about the "indispensability" of American leadership in, well, everything. That is a hoary and out-of-date viewpoint. The United States is a huge problem and should be one of the leaders, but it's increasingly obvious the world can handle the crisis with America as the Great Workaround.
The European Union, with roughly the same population as the United States, emits 10% of global GG emissions. Americans have a lower standard of living than the Germans but use twice as much energy per capita. China is aggressively moving forward with alternative energy, and it's obvious that China, Israel and Germany will dominate the field of alternative energy while the USA continues to debate whether there is a problem, which is not surprising since we have a Congress where well over half the members disagree with basic empirical science on fundamental subjects like evolution. The world has probably never seen such a thing since the days of Galileo. I think it's a serious possibility that the Republican majorities in both houses mostly do not believe that the sun is at the center of our solar system.
Despite the feeble-mindedness at the level of American federal government, our saving grace is that U.S. GG emissions have flatlined because we're broke. Gasoline usage continues to decline despite radically lower prices. I think this is because about 100 million Americans who should be working are not working because there's nothing to do. If you don't have a job to drive to, and no car even if you had the job, the "miles per capita" stat works in your favor. In turn, I think the miserable state of our economy owes to the same stupidity that leads to the composition of the Congress, so the two tend to reinforce each other in a virtuous feedback loop. By remaining stupid and too broke to drive, Americans can make their contribution to solving the dire problem of climate change, and the U.S. percentage of emissions will continue to fall. Fighting foreign wars for no reason, for example, spends a lot of money and is energy-intensive for the military overseas, but does not translate into higher energy use by the people back home, where most of us are. In fact, by wasting all that money that would otherwise be invested, for example, in building a new economy based on alternative energy (as Germany has done), America doubles down on its stupid economy and guarantees that we will not have the wherewithal to contribute much to GG emissions.
Thus, I agree with the Republican position that Obama should not have sent a delegation to Paris. We would have saved the marginal contribution to GG emission from flying Kerry & Co. over there, and the educated people in the world would not have had to tiptoe around the dumbest people in the room. The biggest complaint from the Republicans was that Obama should have been concentrating on the "terrorist" problem, such as stopping the San Bernadino attack that had already happened, rather than wasting resources on an environmental problem that is not real from the U.S. point of view. Keeping our focus on "terrorism," even if we mostly exacerbate the problem by fighting unnecessary wars in the Middle East in the first place, maintains a steady flow of the national treasury to the military industrial complex, which, one must admit, is a bipartisan beneficiary of our political system, and it will be no different under Hillary.
Yet all in all, there is reason to rejoice in this holiday season. The world will move forward without us (as it has been doing for some time, in point of fact) and Americans at the individual or state level (California, for example, is very progressive on issues of climate change, such as AB 32) can do their part to join in with those in the international community who possess the intellectual capacity, and the good faith, to deal with the problem.