Hurricane Katrina caused so much damage because it got warmer in the Atlantic Ocean / Gulf of Mexico.
Here are some quotes.
"As the world warms, we expect more and more intense tropical hurricanes and cyclones," said James McCarthy, a professor of biological oceanography at Harvard University.
"Weather records are being set all the time now. We're in an era of unprecedented extreme weather events," McCarthy said. "In 30 to 50 years' time, the Earth's weather generating system will be entirely different," he predicted.
"Global warming is creating conditions that are more favorable for hurricanes to develop and be more severe," said Kevin Trenberth, head of the Climate Analysis Section at the National Center for Atmospheric Research in Boulder, Colorado.
"This is the first time I have been convinced we are seeing a signal in the actual hurricane data,'' climatologist Kerry Emanuel of the Massachusetts Institute of Technology said in an e-mail exchange. "The total energy dissipated by hurricanes turns out to be well correlated with tropical sea surface temperatures,'' he said. "The large upswing in the past decade is unprecedented and probably reflects the effects of global warming.''
