Is climate change causing an upsurge in US tornadoes?
点击量： 时间：2019-03-14 11:07:01
By Chris Mooney FROM the start of 2008, something seemed amiss with the weather. During an unseasonably warm January, two tornadoes struck Kenosha County, Wisconsin, damaging 105 homes. It was only the second known January tornado strike in Wisconsin. Just a few days later, a tornado struck Vancouver in Washington – only the third January tornado in that state since 1950. Then on 5 and 6 February, a storm system spawned 84 tornadoes across several southern states as their primary elections took place. Five of the tornadoes were powerful EF4s on the so-called Enhanced Fujita scale. The Super Tuesday outbreak was the worst for 23 years, and left 57 dead. Once again, it came unusually early in the year. Unusually warm weather seemed partly to blame. By the end of that month, 2008 already seemed to be one for the record books. Altogether there were 148 tornadoes across the US in February, more than double the previous record for this month, set in 1971. March seemed more normal, apart from an EF2 tornado hitting downtown Atlanta for the first time. Its 10-kilometre rampage racked up $200 million in damage and struck a CNN building, ensuring massive media coverage. In May the drama continued. It is usually a very active month, but for this May the monthly count was a staggering 447 tornadoes. With half the year gone, tornadoes have already killed 119 people. That is nearly as many as in the whole of 1998, when 129 deaths made it the deadliest year since the 1970s. Inevitably, in the face of such extreme weather,