Friday, September 08, 2017

Hurricanes Are Sweeping The Atlantic. What's The Role Of Climate Change?

[NPR] Hurricane Irma is hovering somewhere between being the most- and second-most powerful hurricane recorded in the Atlantic. It follows Harvey, which dumped trillions of gallons of water on South Texas. And now, Hurricane Jose is falling into step behind Irma, and gathering strength.
Is this what climate change scientists predicted?
In a word, yes. Climate scientists such as Michael Mann at Penn State says, "The science is now fairly clear that climate change will make stronger storms stronger." Or wetter.
Scientists are quick to point out that Harvey and Irma would have been big storms before the atmosphere and oceans started warming dramatically about 75 years ago. But now storms are apt to grow bigger. That's because the oceans and atmosphere are, on average, warmer now than they used to be. And heat is the fuel that takes garden-variety storms and supercharges them.
The National Oceanic and Atmospheric Administration predicted that the Atlantic hurricane season this year would be big. They said the most likely scenario would be five to nine hurricanes and three to five major hurricanes, which is above the long-term average.
Some of their reasoning is based on climate change. The eastern tropical Atlantic ocean is the fuel tank of hurricanes, if you will, and big parts of the sea surface have been between .5 and 1 degree Celsius warmer than average this summer. Now, the Atlantic goes through normal cycles of warming and cooling that have nothing to do with climate change, such as in response the El Nino and La Nina weather cycles. But this year neither cycle is active. Read More