Warm sea wa­ter fu­eled 2017 hur­ri­cane sea­son

USA TODAY Weekend Extra - - FRONT PAGE - Doyle Rice Con­tribut­ing: As­so­ci­ated Press

The cat­a­strophic 2017 hur­ri­cane sea­son – which in­cluded such mon­sters as Har­vey, Irma and Maria – was fu­eled in part by un­usu­ally warm ocean wa­ter, a new study sug­gests.

And be­cause of hu­man-caused global warm­ing, the study said, sim­i­lar fa­vor­able con­di­tions for fierce hur­ri­canes will be present in the years and decades to come.

“We will see more ac­tive hur­ri­cane sea­sons like 2017 in the fu­ture,” said lead au­thor Hiro Mu­rakami, cli­mate sci­en­tist and hur­ri­cane ex­pert at the Na­tional Oceanic and At­mo­spheric Ad­min­is­tra­tion.

Last year, six ma­jor hur­ri­canes formed, twice the re­cent av­er­age. By 2100, that av­er­age could soar to five to eight ma­jor hur­ri­canes a year, ac­cord­ing to the study pub­lished Thurs­day in the jour­nal Science.

Sea wa­ter in the main hur­ri­cane de­vel­op­ment re­gion of the At­lantic Ocean av­er­aged 0.7 de­grees warmer than nor­mal for the en­tire 2017 sea­son, which is un­usual for a full six-month pe­riod, Mu­rakami said.

“We show that the in­crease in 2017 ma­jor hur­ri­canes was not pri­mar­ily caused by La Nina con­di­tions in the Pa­cific Ocean, but mainly by pro­nounced warm sea sur­face con­di­tions in the trop­i­cal North At­lantic,” the study said.

La Nina, a pe­ri­odic nat­u­ral cool­ing of the trop­i­cal Pa­cific Ocean, tends to in­crease hur­ri­cane ac­tiv­ity in the At­lantic.

The key fac­tor con­trol­ling At­lantic ma­jor hur­ri­cane ac­tiv­ity ap­pears to be how much the trop­i­cal At­lantic warms rel­a­tive to the rest of the global ocean, ac­cord­ing to the study.

The three big hur­ri­canes in 2017 caused an es­ti­mated $265 bil­lion in dam­age dur­ing a year that shat­tered all records for U.S. eco­nomic losses due to ex­treme weather, NOAA said.

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