The Current Wisdom: Overplaying the Human Contribution to Recent Weather Extremes
The Current Wisdom is a series of monthly posts in which Senior Fellow Patrick J. Michaels reviews interesting items on global warming in the scientific literature that may not have received the media attention that they deserved, or have been misinterpreted in the popular press.
The Current Wisdom only comments on science appearing in the refereed, peer-reviewed literature, or that has been peer-screened prior to presentation at a scientific congress.
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The recent publication of two articles in Nature magazine proclaiming a link to rainfall extremes (and flooding) to global warming, added to the heat in Russia and the floods in Pakistan in the summer of 2010, and the back-to-back cold and snowy winters in the eastern U.S. and western Europe, have gotten a lot of public attention. This includes a recent hearing in the House of Representatives, despite its Republican majority. Tying weather extremes to global warming, or using them as “proof” that warming doesn’t exist (see: snowstorms), is a popular rhetorical flourish by politicos of all stripes.
The hearing struck many as quite odd, inasmuch as it is much clearer than apocalyptic global warming that the House is going to pass meaningless legislation commanding the EPA to cease and desist from regulating greenhouse gas emissions. “Meaningless” means that it surely will not become law. Even on the long-shot probability that it passes the Senate, the President will surely veto, and there are nowhere near enough votes to override such an action.
Perhaps “wolf!” has been cried yet again. A string of soon-to-be-published papers in the scientific literature finds that despite all hue and cry about global warming and recent extreme weather events, natural climate variability is to blame.
Where to start? How about last summer’s Russian heat wave?
The Russian heat wave (and to some degree the floods in Pakistan) have been linked to the same large-scale, stationary weather system, called an atmospheric “blocking” pattern. When the atmosphere is “blocked” it means that it stays in the same configuration for period of several weeks (or more) and keeps delivering the same weather to the same area for what can seem like an eternity to people in the way. Capitalizing on the misery in Russia and Pakistan, atmospheric blocking was added to the list of things that were supposed to be “consistent with” anthropogenically stimulated global warming which already, of course included heat waves and floods. And thus the Great Russian Heat Wave of 2010 became part of global warming lore.
But then a funny thing happened – scientists with a working knowledge of atmospheric dynamics started to review the situation and found scant evidence for global warming.
The first chink in the armor came back in the fall of 2010, when scientists from the Physical Sciences Division (PSD) of the Earth System Research Laboratory (ESRL) of the National Oceanic and Atmospheric Administration (NOAA) presented the results of their preliminary investigation on the web , and concluded that “[d]espite this strong evidence for a warming planet, greenhouse gas forcing fails to explain the 2010 heat wave over western Russia. The natural process of atmospheric blocking, and the climate impacts induced by such blocking, are the principal cause for this heat wave.”
The PSD folks have now followed this up with a new peer-reviewed article in the journal Geophysical Research Letters that rejects the global warming explanation. The paper is titled “Was There a Basis for Anticipating the 2010 Russian Heat Wave?” Turns out that there wasn’t.
To prove this, the research team, led by PSD’s Randall Dole, first reviewed the observed temperature history of the region affected by the heat wave (western Russia, Belarus, the Ukraine, and the Baltic nations). To start, they looked at the recent antecedent conditions: “Despite record warm globally-averaged surface temperatures over the first six months of 2010, Moscow experienced an unusually cold winter and a relatively mild but variable spring, providing no hint of the record heat yet to come.” Nothing there.
Comments on Criticism of Cato Ad
Our friends at www.realclimate.org and www.ryanavent.com have been taking shots at the statements in our ad, so I’d like to offer a little commentary.
We make three factual assertions.
First, we say that “surface temperature changes over the past century have been episodic and modest”. We cite Brohan et al., Journal of Geophysical Research (2006 and updates) and Swanson and Tsonis, Geophysical Research Letters, 2009. The first is the latest update of the East Anglia temperature history, which long has been the IPCC staple. It is the one most cited over the years by the IPCC because it was the first long history that contained much more than simply World Weather Records data updated with local records at the end of a month. At any rate, both it and other global histories indeed show modest warming, about 0.8degC from 1900-2000, and indeed it is episodic. Everyone (well probably almost everyone…there are some real people who don’t believe it is right) pretty much agrees that there are two periods of warming, 1910-45 and 1977-98, with a slight cooling in between and no trend after. If that’s not “episodic”, I don’t know what is. The Swanson paper in fact specifically quantifies these episodes. The paragaph near the end of it that says this may mean that warming will be faster than we thought was pure speculation. It could just have easily been argued (as I do) that the lack of recent warming more likely indicates that 21st century warming will be lower than forecast by oceanic feedback because lack of warming simply delays any water vapor amplification. Pure and simple.
The second assertion is that, “after controlling for population growth and property values, there has been no increase in damages from severe weather events”. The citation is short — a note in the Bulletin of the American Meteorological Society, by Pielke Jr. et al, 2005. The et al. numbers over ten other large-name scientists/analysts, and the reference list is the important part. There are a large number of citations on climate-related damages for various places and/or periods. We couldn’t list them all in this format, so we chose a single citation that could be consulted and an interested reader would find all the subsidiary supporting material.
Finally we state that “the computer models forecasting rapid temperature change abjectly fail to explain recent climate behavior”, citing Douglas et al., International Journal of Climatology, 2007, which showed the major disparity between forecasts of the upper tropospheric tropical “warm spot”, a hallmark of greenhouse projections, and observations in the radiosonde record. Yes it is true that Santer et al. have published a lengthy rebuttal, but it is extremely dense and marks just another go-round-and-round over this issue. Douglas et al. have a response but it hasn’t been published yet. The debate will go on and on. Further, it is quite apparent from comparing midrange multimodel estimates from the IPCC to observed temperatures, and those indeed projected for coming years, that there is a signficant disconnect developing between the models and surface temperature. They simply don’t anticipate multidecadal periods without warming. Oh yes, since this has happened, all of the sudden models can be forced to “explain” it, but that’s not prospective. Instead, it is retrospective adjustment. Such work wouldn’t be performed if there weren’t something wrong.
That’s more than enough to negate President-elect Obama’s statement that “The science is beyond dispute and the facts are clear”!
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