By Michael McCarthy and Abigail Townsend
http://news.independent.co.uk/environment/article1521855.ece<snip>
Professor Kerry Emmanuel of the Massachusetts Institute of Technology caused a stir with a paper published in Nature just three weeks before Katrina hit, in which he said that hurricanes had doubled in power since 1950, with most of the increase in force occurring in the past 30 years.
Another paper published in September 2005 reported that the number of category 4 and 5 hurricanes - the strongest - had almost doubled in number over the same period.
But not all researchers accept those conclusions (which, incidentally, are very unwelcome to the Bush administration with its continuing stance of de-emphasising the potential effects of global warming). Some doubt has been cast on the accuracy of earlier hurricane data, which might make comparisons invalid. One observer who is following the debate closely is the authoritative British science writer Fred Pearce, who has just published a study of the latest climate change research entitled The Last Generation. "Not every hurricane researcher is convinced," he said. "Some think we may be seeing no more than natural fluctuations in hurricane activity. And they say that we can't be sure how many hurricanes there were, and how strong they were, 30 or 40 years ago.
"But the evidence is growing ever stronger that hurricanes are becoming more intense, and maybe more frequent too, as a result of global warming...