Is climate change making hurricanes more powerful?

Should there be a Category 6 for hurricanes?

In 169 years of record keeping, there have been only 35 Category 5 hurricanes in the Atlantic. Five of those catastrophic storms happened in the last four years — including Hurricane Dorian, which smashed into the Bahamas before stalling and unleashing devastating rain and wind.

And while there's not conclusive evidence that climate change is making hurricanes move more slowly, there is "probably" a connection between the two, according to CBS News climate and weather contributor Jeff Berardelli.

"First, I have to say that storms stall naturally. Harvey stalled naturally, Florence stalled naturally, and Dorian stalled somewhat naturally," Berardelli said. "However, there's research to support that Atlantic hurricanes are slowing down their forward speed by around 16%."

That research comes from James Kossin, a researcher at NOAA, Berardelli said. "[Kossin] surmises that it probably has to do with climate change," he said, "but it is something that we need to look more deeply into."  

There's also reason to believe that climate change is making hurricanes more powerful.

"Water temperatures are getting warmer, right? All over the world. And that is high-octane fuel to power stronger storms. So we see a trend in more Category 4s and Category 5s," Berardelli said.

"Now, some of that is questionable, just simply because before the advent of satellites, we may have missed Category 4s and Category 5s in the early 1900s and the 1800s," he added. "With that said, there seems to be a fairly robust signal that we're seeing more intense hurricanes."

That trend is likely to continue. "Almost all the research shows that in the future, hurricanes are likely to get more intense," he said. "But we may not see more of them, just a higher proportion of Cat 4s and Cat 5s — those are the most destructive. "

That's a big problem. "Compare a storm with winds of 185 mph, like Dorian, with a low-end hurricane [with] winds at 75 mph, like Barry," Berardelli said. "It's not double the amount of damage, it's not 20 times the amount of damage, it's not 100 times the amount of damage — it's over 1,000 times the damage."

Given the potential for more high intensity hurricanes, some scientists have suggested adding a Category 6 to the measurement scale.

"This is something meteorologists are debating a lot over the past couple years because of these monster storms kind of pushing at the top end of Category 5," Berardelli said. "But this is what I would say: if you want to send a message, as a scientific community, because we keep getting these really intense hurricanes – and they're getting stronger and reaching that top end [of] 5 — if you want to send a message about climate change, the best way to do it is to add another category."