Scientists connect global warming to extreme rain

EXTREME rainstorms and snowfalls have grown substantially stronger, two studies suggest, with scientists for the first time finding the telltale fingerprints of man-made global warming on downpours that often cause deadly flooding.

Two studies in Wednesday's issue of the journal Nature link heavy rains to increases in greenhouse gases more than ever before.

One group of researchers looked at the strongest rain and snow events of each year from 1951 to 1999 in the Northern Hemisphere and found that the more recent storms were 7 per cent wetter. That may not sound like much, but it adds up to be a substantial increase, said the report from a team of researchers from Canada and Scotland.

The study did not single out specific storms but examined worst-of-each-year events all over the Northern Hemisphere. While the study ended in 1999, the close of the decade when scientists say climate change kicked into a higher gear, the events examined were similar to more recent disasters: deluges that triggered last year's deadly floods in Pakistan and in Nashville, Tennessee, and this winter's paralysing blizzards in parts of the United States.

The change in severity was most apparent in North America, but that could be because that is where the most rain gauges are, scientists said. Both studies should weaken the argument that climate change is a 'victimless crime,' said Myles Allen of the University of Oxford.

He co-authored the second study, which connected flooding and climate change in Britain. Not all the extreme rain and snow events the scientists studied cause flooding. But since 1950, flooding has killed more than 2.3 million people, according to the World Health Organization's disaster database.