The science is extremely clear: Global warming may not affect the frequency of hurricanes, but it makes the average hurricane stronger, magnifying its destructive power. In the years ahead, there will be more storms like Katrina, unless we change course. Indeed, we have had two more Category 5 storms since Katrina -- including Wilma, which before landfall was the strongest hurricane ever measured in the Atlantic.
We know that hurricanes are heat engines that thrive on warm water. We know that heat-trapping gases from our industrial society are warming the oceans. We know that, in the past 30 years, the number of Category 4 and 5 hurricanes globally has almost doubled. It's time to connect the dots:
Last year, the science textbooks had to be rewritten. They used to say, "It's impossible to have a hurricane in the South Atlantic." We had the first one last year, in Brazil. Japan also set an all-time record for typhoons last year: 10. The previous record was seven. This summer, more than 200 cities in the United States broke all-time heat records. Reno, Nev., set a new record with 10 consecutive days above 100 degrees. Tucson, Ariz., tied its all-time record of 39 consecutive days above 100 degrees. New Orleans -- and the surrounding waters of the Gulf -- also hit an all-time high.
This summer, parts of India received record rainfall -- 37 inches fell in Mumbai in 24 hours, killing more than 1,000 people.
The new extremes of wind and rain are part of a larger pattern that also includes rapidly melting glaciers worldwide, increasing desertification, a global extinction crisis, the ravaging of ocean fisheries, and a growing range for disease "vectors" like mosquitoes, ticks and many other carriers of viruses and bacteria harmful to people.
All of these are symptoms of a deeper crisis: the "Category 5" collision between our civilization -- as we currently pursue it -- and the Earth's environment.
The entire speech is well worth your time: