By Lawrence Solomon May 1, 2011
Tornadoes are associated with episodes of great temperature contrasts, often involving unseasonably cold air colliding with warm air. During the 1960s and 1970s, when global temperatures cooled so much that scientists believed we were entering a period of global cooling , the number of tornadoes rose. 1973, which saw 1100 tornadoes in the U.S., was dubbed The Year of the Tornado, only to be followed by the fiercer Widespread Tornado Outbreak of 1974: Of that year’s 148 tornadoes, 118 tore up swathes of at least one mile in length and claimed 330 deaths. As temperatures rose in the following decades, tornadoes steadily declined in number.
Over the last decade, global temperatures stopped rising and have begin to fall. And tornadoes could once again be on the rise, a sign of the global cooling trend that many climate experts have been anticipating.
Reports of cooler temperatures this spring abound. In Canada and the U.S., planting schedules have been delayed . On the other side of the world, fruit farmers in India fear the cold will destroy their crops and yesterday’s Vietnam News warned of a “poor harvest [due] to harsh weather conditions and a prolonged severe cold spell when the rice was being planted.”
All told, according to climatologist Roy Spencer’s excellent blog, “The global-average temperature has plummeted by about 1 deg. F in just one year.” Rather than tornadoes being caused by global warming, as some claim, Spencer states that “if anything, global warming causes FEWER tornado outbreaks…not more. In other words, more violent tornadoes would, if anything, be a sign of ‘global cooling’, not ‘global warming’.”
If the tornadoes are an indicator of global cooling, these would be ill winds, indeed. Apart from the immediate deaths and devastation that tornadoes leave in their wake, cold weather reduces agricultural output, and costs some 40,000 lives a year, according to a Stanford University study.
Lawrence Solomon is executive director of Energy Probe and the author of The Deniers. LawrenceSolomon@nextcity.com.