I'm Not Sure the Data Means What You Think It Means

Over at Climate Skeptic, I discuss a recent claim by ABC that year-to-date tornado frequency has nearly doubled vs. 2007, and that this is because of global warming.  I will take their word for it that tornado frequency is up, but there is one tiny problem:  The US in Jan-Apr of this year was almost a full degree cooler than last year.  So if tornado frequency is up, and ABC is correct that yearly changes in this metric are due to changes in global temperature, then it can only mean that global warming reduces, rather than increases, tornadoes.


  1. Rob:


    Your logic only holds true if you work for a major media outlet and/or the IPCC. :P

  2. Phil:

    Tornadoes arise from the clash of three airmasses: a warm and moist airmass, a cold airmass, and a dry airmass coming up from the southwest. Global warming/cooling/climate change would increase the frequency of tornadoes if it altered the three types of airmasses differentially. If it has a more-or-less uniform impact on them, it shouldn't alter tornado frequency.

  3. Russ:

    In addition to the fact that nothing really blocks cold Canadian air masses from slamming into the very warm Gulf of Mexico, the jet stream can cause a twisting motion where the cold/warm air masses meet. Other than that, I think we are looking at a statistical aberration.