Extreme Atlantic hurricane seasons more likely as ocean warms

TAMPA, Fla. (WFLA) — Over the past couple of decades, the Atlantic basin has seen an unusual number of hyperactive hurricane seasons.

Now a new study says a warming ocean is the culprit.

In the graphic below, you can see that since 1970 the main development region of the Tropical Atlantic has warmed by almost 2 degrees Fahrenheit. That’s fueling stronger hurricanes.

To define how active a hurricane season is meteorologists use a metric called accumulated cyclone energy – or ACE. Surpassing 160 units of ace is considered hyperactive. In this graphic below you can see that recent seasons have had higher ace.

The research team used computer models to simulate what recent seasons would have looked like without warming and then compared that to what actually occurred.
The conclusion: extreme Atlantic hurricane seasons – ones with ace of 160 or greater – were made twice as likely by ocean warming.

WFLA’s Chief Meteorologist and Climate Specialist spoke to the lead author of the study, Peter Pfleiderer from Climate Analytics, in Berlin.

“What we have seen already is that seasons with very intense storms and major hurricanes are getting more likely,” Pfleiderer said. “So this doesn’t mean there are more storms in general per season, but these storms that are able to cause a lot of impacts and a lot of damages are major hurricanes and the intensification of these hurricanes are increasing.”

That’s an important point: global warming is not causing more hurricanes. In fact, this new paper shows just the opposite. The number of storms are decreasing, but a greater percentage of storms that form are becoming stronger hurricanes, leading to more damage.