Twisted Logic

Here’s the underlying fact pattern: “In 2011, the United States saw its second-deadliest tornado season in history: Nearly 1,700 tornadoes killed 553 people. The Joplin, Mo., twister was the single deadliest in American history, killing 158 people and causing $2.8 billion in damage… The following year, 2012, started even earlier and even busier. Through April there were twice as many tornadoes as normal. Then the twisters suddenly disappeared. Tornado activity from May to August of that year was the lowest in 60 years of record-keeping, said Harold Brooks, a top researcher at the National Weather Center in Norman, Okla… Meanwhile, Canada saw an unusual number of tornadoes in 2012; Saskatchewan had three times the normal number.” Huffington Post on the Ides of March.

Here’s the question: is the above acceleration of dynamically destructive weather patterns a result of climate change? And the answer is… no one is really sure. Statistically, you certainly can make a case for it. But scientists haven’t really found a clear provable link. Heat alone isn’t the cause, since these twisters accumulate more in spring and tend to reduce as the summer heat intensifies. Is global warming pushing spring to earlier months? The lesser number of tornadoes in drought-claimed areas (absence of water) is also a factor. How about the increasing movement, north and south, of the Gulf Stream? Global warming?

“Tornado record-keepers tally things like the most and least tornadoes in a month. Records for that category have been set 24 times over the past 60 years. Ten of those records have been set in the past decade – six for the fewest tornadoes and four for the most, Brooks said. Also, the three earliest starts of tornado season and the four latest have all occurred since 1997, he said…

“A new study in the Bulletin of the American Meteorological Society looks at all sorts of extreme weather, how it is changing because of global warming and how things are predicted to change in the future. The study says tornadoes and the severe thunderstorms that spawn them are the hardest to predict…Public opinion polls show Americans blame global warming for bad tornado outbreaks, but climate scientists say that’s not quite right.

“One reason scientists can't figure out how global warming might affect tornadoes is that twisters are usually small weather events that aren't easily simulated in large computer models. And records of tornadoes may not have been accurate over the years as twisters twirled unnoticed around unpopulated areas.” Huffington Post.

So today, the emphasis is less on prediction but on understanding what happens to flying debris and funnel movement once a storm hits. Trying to ascertain where people near a building tornado (or one that is striking hard) must be warned or protected. This is particularly relevant where you have a toxic debris sucked up into the vortex flying to “who knows where” to be deposited with obviously harmful results. By examining debris dispersion, scientists are beginning to understand the phenomenon better. In the end, global warming could easily be a factor but perhaps not a cause? We just don’t know, but asking these questions and exploring the answers is simply good science.

I’m Peter Dekom, and the complex interplay of natural barriers is both fascinating… and potentially deadly.