Wednesday, January 8, 2014

Does The Polar Vortex Over The Eastern United States Mean Global Warming Is Over?

Not particularly.  Record temps are going on in Australia, and it has been warmer over the North Pole and in Moscow than in parts of the eastern US.  November set an all time record for world average temperature and December was well above long term averages, despite it being colder than normal in that all important eastern US.

That noted, it must be recognized, and has been by serious climate watchers, that indeed the rate of increase of average global temperature has slowed substantially in the last 10 years, if not completely halted, although the global warming deniers spout on about it being 15 years, which is not the case given that 1998 was an outlier way on the upside.  In any case, global average air temperature is not clearly rising at this time, even as the polar vortex now exiting the US does not prove this.

However, this does not mean that global warming has stopped.  Curiously enough, warming above that predicted appears to be happening in the oceans below 700 meters.  The main models used by the IPCC observers model the air, the surface water, and the deep water.  Air is now not warming as much as predicted, but the deep ocean is doing more so than predicted.  Looking at the total surface, it looks like warming is still going on, although I recognize that the models are not doing a good job of explaining why we should be seeing this particular pattern.  But one must expect that warming at the depths will at some point manifest itself in the higher levels.  Maybe we do not need to worry about warming of the air for a few years, but we may well face much worse warming of the air in the not too distant future when this comes bubbling up, as it were.

There is also the matter discussed by Martin Weitzman in Philadelphia about how climate outcomes probably exhibit fat tails due to nonlinear dynamics effects.  But we do not know how to deal with such matters in policy terms.

Finally, I am not going to take sides in the matter of what the polar vortex shows or what caused it.  There is a serious argument that it may be due to global warming, the "warm ocean, cold continent" effect theory, which others dispute.  However, there is also the fact that contrary to the claim of Rush Limbaugh that the term "polar vortex" was cooked up for this particular event, its first use appears to have been in 1974 when it was invoked as part of the then seriously considered theory that we were moving into a new ice age and was part of that.

BTW, I have noted this before, but will repeat it again, just in anticipation of somebody handing me the standard story.  Yes, by 1974 and certainly the later 70s, the ice age theory was falling out of fashion and not appearing in academic papers, basically a media scare phenomenon by then, although in fact it was not until about the mid-70s that global average temperatures began to rise again after a period of gradual decline starting in the 1940s.  However, there was a close debate over global warming versus cooling in the early 70s, with the academic papers evenly split in 1971.  It was CO2 versus aerosols.  What tilted the argument was that aerosols fall out of the atmosphere quickly, whereas CO2 does not.  But this was not factored in properly in 1971 and in fact global cooling was going on, so there was a real debate at that time, even though it was basically over by 1975.


Wallfly said...

The thing about the ice age theory, recalling from grade school, was that climatologists first encountered evidence of a relatively rapid onset of earlier Ice Ages in the late 60's(and as far as I know the idea that the start of glaciation can start much more quickly than the pre-1970's view is still valid).

Yeah, lots of media scare, though I also think some academics were anxiously impressed by the fact that the onset of an glaciation might not be at all gradual. said...


You are right. In the early 70s I worked for the late Reid Bryson, one of the main climatologists who found the evidence for this rapid entry (and exit) from glacial periods. This is still accepted, and is one of the pieces of evidence for Weitzman's argument for fat tails in climate outcome distributions, with the many positive feedbacks in the complex nonlinear climate system easily able to generate such outcomes.

Shag from Brookline said...

Is Gore-Tex the answer to polar vortex? Recall the Seinfeld episode with George Costanza wearing a Gore-Tex bulky jacket on a cold NYC night. Query: Was Gore-Tex named after Al Gore in response to his global warming claims? said...


It is really unfortunate in my view that Gore became so strongly identified with this issue. It contributed to the partisanizing of it that has led us to the point where any sort of action by Congress is now impossible, given that the GOP has been taken over by deniers, although the latter might have happened anyway due to the influence of certain corporate interests.

It is also the case that he was wrong about some things, which has made this easier for those crticizing him on partisan grounds. Thus, he made a big deal about Katrina, but there is no scientific consensus about the impact of warming on hurricanes. It looks like it might increase intensity of them due to warmer oceans, with both Katrina and Sandy examples. But this is offset by a tendency to have fewer, dramatically seen in 2013 due to warming leading to more sand coming out of Africa in the air, which tends to suppress hurricanes. One rarely hears about that, even after the flop this past year of some people making forecasts of a massive hurricane season that did not happen.

BTW, the scientific consensus that warming is happening remains in place, despite the last decade not clearly having a warming trend in the atmosphere. But this has already been explained in my main post.