[First posted at Forbes.]
The year 2012 is breaking all-time records for lack of tornado activity, inviting the question whether global warming is causing a long-term decline in destructive extreme weather events.
According the National Oceanic and Atmospheric Administration, only 12 tornadoes touched down in the United States during July 2012, shattering the previous July record low of 42 tornadoes recorded in 1960. Because radar technology in 1960 could not detect many of the smaller tornadoes that are detectable today, scientists believe the actual number of tornadoes that occurred in the previous record-low July 1960 was actually about 73. Accordingly, six times more tornadoes occurred in July 1960, the previous record-low year, than occurred in July 2012.
Similarly, less than 300 tornadoes were recorded in this year’s peak tornado season, which runs from mid-April through late-July. Approximately 850 tornadoes touch down during the peak season in an average year. Accordingly, three times more tornadoes occur during an average peak-tornado season than occurred in 2012.
Harold Brooks, a research meteorologist at the National Severe Storms Laboratory, says the lack of tornado activity is due to warm, dry weather in the American Midwest and a northerly tracking jet stream this year. These two factors have also reduced the number of strong thunderstorms that global warming alarmists claim are made more frequent and severe by global warming.
National Oceanic and Atmospheric Administration data show a long-term decline, at least since the mid-1970s, in strong tornadoes. This decline in strong tornadoes began precisely when global temperatures rebounded from a 30-year cooling spell.
Although strong tornado activity is declining in sync with the recent modest rise in global temperatures, global warming alarmists frequently assert that whenever one of the ever-less-frequent tornadoes occurs, global warming must be to blame. This is typical of the tactics of global warming alarmists, who rarely miss an opportunity to misrepresent scientific facts to further their political agenda.
After some tornadoes touched down in March of this year, for example, Brad Johnson of the leftist activist group Center for American Progress wrote an article tying the tornadoes to global warming. “In the face of this warning, we must ask if our current path of increased pollution and decreased investment in public safety is the wisest course,” wrote Johnson.
Similarly, CNN meteorologist Alexandra Steele told viewers in April of this year that global warming was responsible for tornadoes that touched down in the Dallas area that month.
Tornadoes are becoming less frequent and less severe as our planet modestly warms. Yet global warming alarmists focus attention on the few tornadoes that still do occur and say that global warming is causing these increasingly rare tornadoes. The true question, however, is not whether global warming is causing more tornadoes, but whether the declining frequency and severity of tornadoes is being caused by global warming.