Another Shabby Attempt to Tie Increased Tornadoes to Global Warming

The paper, Tornado Activity is Occurring Earlier in the Heart of “Tornado Alley” brings up some interesting points about the peak of tornado season occurring earlier in the spring in the conventional “tornado alley” of the Great Plains.  The paper is an attempt to link global warming to a change in tornado season between 1954 and 2009. Its primary conclusions appear sound. That result is not surprising given the rise in global temperatures during that period of time (see graph).

 

My objections are not with the primary thrust of the paper. It appears to be a useful addition to the literature.

My objection is the paper’s attempt to make the change in the time of the peak tornado season into something sinister. For example, the first sentence in the paper (it appears in the Abstract) is, “Tornado frequency may increase as the factors that contribute to severe convection are altered by a changing climate.” It also says, “The lack of evidence is due in part to sampling effort: the number of reported tornadoes has increased over time [Dixon et al., 2011].” The reference to Dixon has to do with Dixie tornado alley, not the one in the Great Plains. 

So, let's go through this yet again. Let’s begin with all tornadoes of F-1 intensity or greater:

Even though world temperatures have risen, there is absolutely no upward trend in tornadoes. This is especially surprising given the storm chase program that started in 1972 and Doppler radar installations beginning in 1991. There are many small tornadoes that now get into the books that never would have been recorded a half-century ago. 

Data from NOAA, I added 2013

In the case of tornadoes of F-3 or greater, there is a surprising downward trend. Since the Fujita Scale is a damage scale, meteorologists believe we have a reasonable grasp of the number of strong tornadoes since the mid-50’s.

This is the first time non-scientific techniques have been used to try to produce the 'global warming produces more tornadoes' result. A 2013 paper, Robust Increases in Severe Thunderstorm Environments in Response to Greenhouse Forcing, mis-stated the findings of a United Nation's report on severe storm to get around the fact that, so far, warmer temperatures have meant fewer tornadoes. 

Instead of accepting what the data says, research have distorting the record to try to tie more tornadoes to global warming. And, unfortunately, journalists (which seem to unquestioningly accept anything the pro-global warming advocates publish) allow them to get away with it.