Climate-Cyclone Link Spurs Debate

May 6, 2008 -- Climate scientists have begun to debate whether global warming is producing more powerful storms, after Nargis smashed into Myanmar -- brutally changing gear from a Category One to a Category Four cyclone just before it made landfall.

Nagris wasn't an isolated incident: Hurricane Katrina laid waste to parts of the U.S. Gulf Coast in 2005.

And in 2007, the Arabian peninsula was hit by a super-cyclone, Gonu.

Are these events -- massively costly in lives and treasure -- all linked?

Could they be part of an alarming trend of weird, more powerful storms stoked by global warming?

That's a question that causes fierce jousting among climate scientists.

Experts agree that a single weather event cannot be pinned to climate change, which is part of a long-term pattern spanning decades or centuries.

"It's impossible to say," Adam Lea of the Benfield UCL Hazard Research Center at University College London said.

"It's only in the long term that you get the perspective that lets you say whether an extreme event is part of a wider trend," said French researcher Herve Le Treut, who contributed to last year's landmark report by the U.N.'s Intergovernmental Panel on Climate Change (IPCC).

But that's where the scientific consensus ends.

Some experts argue the evidence is already hard enough to identify a probable trend: storms are becoming more powerful as global warming heats up the oceans.