Blowin in the wind: Despite what our learned president, our erudite Congress and the Republican Party’s science lackeys say, climate change is warming the oceans, providing the energy to generate more powerful hurricanes and cyclones, or “hypercanes.” This according to a new study published in the journal Science last week.
The study noted that the number of Category 4 and 5 hurricanes worldwide has nearly doubled over the past 35 years.
“Warmer sea surface temperatures have increased the amount of water vapour, which is the fuel for hurricanes,” said study co-author Peter Webster of Georgia Institute of Technology’s School of Earth and Atmospheric Sciences.
The largest increases in the number of intense hurricanes occurred in the North Pacific, Southwest Pacific and the North and South Indian Oceans, with slightly smaller increases in the North Atlantic Ocean.
Hurricane Katrina offers a good illustration of the role of warm water, Webster said in an interview with Inter-Press News Service.
Before it struck the U.S. Gulf Coast, Hurricane Katrina made landfall in Florida as a Category 1. However when it crossed over into the Gulf of Mexico, there was a huge, deep pool of very warm water that served as the storm’s high-octane fuel, he said.
Practically overnight, Katrina turned into a Category 5 super storm.
The Saffir-Simpson scale rates hurricanes from 1 to 5 according to wind speeds and destructive potential. A Category 1 storm has winds blowing continuously above 110 kilometres an hour: A Category 5 has continuous winds above 250 kilometres per hour.
At landfall, Katrina weakened to a Category 4. But with its exceptionally large size, the damage it caused will cost the U.S. at least $200 billion.
The North Atlantic is exceptionally hot this year — about 1.5 degrees C warmer than average — and that’s why double the normal number of hurricanes and tropical storms have been forecast. The extra heat translates into an average intensity of these storms that is likely to be 15% to 20% higher.
What will the future be like when the oceans warm another 0.5 degrees C, as they inevitably will even if all human emissions of greenhouse gases were cut off today?
More Category 4 and 5 storms and possibly beyond that towards what meterologists have called “hypercanes.”
Hypercanes is a speculative attempt to explain mass species extinctions 245 million years ago. Computer models showed that continent-sized super-storms with winds averaging 600 kilometres per hour could be produced if oceans warmed to an incredible 45 to 50 degrees C. Such temperatures are impossible today barring a massive meteor strike or gigantic underwater volcano eruption.