Sen. Bill Nelson bluntly assigned blame for how an October tropical storm swiftly grew into the most powerful hurricane to ever hit the Florida Panhandle: It's global warming.

Speaking on CNN on Thursday, Nelson said Florida risks more devastation in its future if it doesn't soon adapt to rising temperatures and sea levels.

"Listen to the scientists at the National Hurricane Center," Nelson said. "Listen to the scientists at the National Weather Service, and they'll tell you that the Earth is heating up and the ferociousness of these storms is as a result, in part, of that heating up of the Earth."

Florida Sen. Bill Nelson on Hurricane Michael: "The Gulf of Mexico was four degrees hotter than is usual ... Listen to the scientists ... and they'll tell you that the earth is heating up and the ferociousness of these storms is as a result, in part, of that heating up" pic.twitter.com/A7O5419019 — New Day (@NewDay) October 11, 2018

Storm trackers said the Gulf of Mexico was an unseasonably warm 84 degrees — 2 to 4 degrees hotter than normal — which contributed to Hurricane Michael growing into a Category 4 with wind speeds of 155 mph before it slammed into the Panhandle coast.

READ MORE: Four reasons why Hurricane Michael was so devastating

Hurricane Michael is the fourth most powerful hurricane to ever hit the United States, according to wind speed measurements, and it is the strongest October storm on record.

The average gulf temperature has risen consistently over the last few decades. Winter 2017 was the first time the average sea surface temperature never fell below 73 degrees in the gulf.

Michael, Nelson said, "picked up in a short period of time, that extra strength fueled from that hot water of the Gulf of Mexico, and then that was what was so surprising to everybody and so deadly as it approached the coast."

POLITIFACT: What we know about climate change and hurricanes.

Last week, United Nation scientists warned that global temperatures over the coming years will rise more swiftly than expected. Drastic action within the next decade is necessary, they said, or extreme heat and powerful weather events will grow increasingly common.

"Florida is ground zero," Nelson said. "Look what's happening down in South Florida on the mean high tide that is sloshing over the street curbs in places like Miami Beach."

"We've got to be clearheaded as we approach each storm season because this is what we are increasingly going to be facing," he added. "And as a result, we're going to have to adapt to that, instead of living in the past, we're going to have to adapt to that in our building standards and our location of structures in the future."