March 18, 2013
Experts Struggling To Predict Climate Change’s Impact On Tornado Season
redOrbit Staff & Wire Reports - Your Universe Online
Two years after from the second-deadliest tornado season in US history, climate scientists are finding it difficult to predict exactly what kind of impact global warming will have on the prevalence of the deadly twisters.
In 2011, nearly 1,700 tornadoes were spotted across America, killing more than 550 people, Associated Press (AP) Science Writer Seth Borenstein reported on Friday. One of those twisters killed 158 people in the city of Joplin, Missouri — causing $2.8 billion in damage and becoming the single deadliest tornado in US history.
“The following year, 2012, started even earlier and even busier,” Borenstein said. “Through April there were twice as many tornadoes as normal. Then the twisters suddenly disappeared.” In fact, Harold Brooks, a researcher at the National Weather Center in Norman, Oklahoma, told the AP that the tornado activity from May through August of last year was the lowest in six decades worth of record-keeping.
“As the traditional tornado season nears, scientists have been pondering a simple question: Will there be more or fewer twisters as global warming increases? There is no easy answer,” said the AP reporter. “Lately, tornado activity in America has been Jekyll-and-Hyde weird, and scientists are unsure if climate change has played a role in recent erratic patterns“¦ [and] the last two seasons aren't alone in illustrating extremes in tornado activity.”
Borenstein explained that tornado-related records are kept in several different categories, including the highest and lowest amount of twisters in a month. Over the past 60 years, those records have been set a total of 24 times, and 10 of those have come within the past decade. The records for the fewest tornadoes in a month have been set six times, and records for the most have been set four times, Brooks told the wire service. In addition, the three earliest and four latest tornado season starts have all happened over the past 15 years.
At one point during the last year´s tornado season, 80 twisters were spotted at various locations throughout the US on a single day, according to a March 2012 report by Sharon Begley of Reuters. While that took place roughly two months before the record drop off in tornado activity, experts chimed in and offered their predictions that earlier-than-normal tornado outbreaks would become more common thanks to climate change.
“As spring moves up a week or two, tornado season will start in February instead of waiting for April,” climatologist Kevin Trenberth of the National Center for Atmospheric Research (NCAR) said at the time. Likewise, Purdue University atmospheric scientist Robert J. Trapp told Reuters that “the number of days when conditions exist to form tornadoes is expected to increase” as a result of global warming. Only time will tell whether or not their predictions will turn out to be true, or not.