Lee intensified into a Category 5 hurricane Thursday night at a historic rate, adding to a string of extremely strong hurricanes this year and the past few decades that experts say are signs of a climate crisis.

Lee is the eighth Category 5 hurricane to make landfall in the North Atlantic since 2016, making up 20% of all hurricanes recorded in the basin in the past seven years, according to the program. CNN Analysis of the NOAA Hurricane Database.

In fact, Category 5 hurricanes have already formed this year in all seven ocean basins where tropical cyclones occur, including Hurricane Joa, which rapidly strengthened to a Category 5 earlier this week.

“The increase in Category 4 or 5 hurricanes, especially the ones we’ve seen with rapid intensity in the past two years, is a sign of climate change, which we expect to happen in a warming world,” Kevin Reed, a hurricane expert and professor at Stony Brook University’s School of Ocean and Atmospheric Sciences, told CNN. explained.

Jim Kosin, a hurricane expert at the University of Wisconsin-Madison and the First Street Foundation, a Brooklyn-based nonprofit, agrees. He cautions that the NOAA database did not fully record hurricanes before the satellite era, and that although technological advances have made it easier to measure hurricanes, it is still difficult to detect the true trend.

However, he noted, the faster the oceans warm, the more intense tropical cyclones are likely to occur. Produce often.

“There are more Category 5 hurricanes now than there were 40 years ago,” Kosin told CNN.

The main way tropical cyclones reach Category 4 or 5 status is through a rapid intensification process, when winds rapidly strengthen to 56 km/h in 24 hours or less, Reid said.

It’s one way experts say the climate crisis has made hurricanes more dangerous, as warmer water allows storms to strengthen faster and reach greater categories of hurricane size. According to the National Oceanic and Atmospheric Administration, Over 90% of global warming over the past 50 years has occurred in the oceans.

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