Lee joins growing trend of intense hurricanes boosted by warmer.webp

Lee joins growing trend of intense hurricanes boosted by warmer oceans

(CNN) – Lee strengthened quickly and at historic speed, becoming a Category 5 hurricane overnight Thursday, adding to a series of extremely strong hurricanes this year and over the past few decades that experts say are a symptom of the climate crisis.

Lee is the eighth Category 5 hurricane to hit the North Atlantic since 2016, meaning 20% ​​of recorded Category 5 hurricanes in the basin have occurred in the past seven years, a CNN analysis of the database shows. NOAA Hurricane Report.

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

“The increase in Category 4 or 5 cyclones, particularly those we have seen with rapid intensification in the last two years, is a telltale sign of climate change, which is exactly what we expect in a warmer world,” said Kevin Reed, a hurricane expert and professor in the Department of Marine and Atmospheric Sciences at Stony Brook University, told CNN.

Jim Kossin, a hurricane expert at the University of Wisconsin-Madison and the First Street Foundation, a Brooklyn-based nonprofit, agrees. He warns that the NOAA database does not fully capture pre-satellite hurricanes and that while advances in technology have made it easier to measure hurricanes, it is still difficult to determine the true trend.

Still, given the rapid warming of the oceans, high-intensity tropical cyclones are likely to become more common, he noted.

“There are very likely more Category 5 hurricanes today than there were 40 years ago,” Kossin told CNN.

Tropical cyclones reach Category 4 or 5 status primarily through a rapid intensification process in which winds increase rapidly to at least 35 mph (56 km/h) in 24 hours or less, Reed said.

It’s just one of the reasons experts say the climate crisis has made hurricanes more dangerous, as warmer water causes storms to intensify faster and reach higher categories on the hurricane scale. Hurricane wind speed. According to the National Oceanic and Atmospheric Administration, more than 90% of global warming over the past 50 years has taken place in the oceans.

“Simply put, as sea surface temperatures warm due to human-caused greenhouse gas emissions, the likelihood of a rapid intensification of an event increases,” Reed said.

The closer storms get to land, the faster they intensify, making them more difficult to prepare for. Hurricane Idalia quickly intensified to 55 miles per hour in 24 hours before making landfall late last month as a Category 4 hurricane along the area of ​​northwest Florida known as Big Bend.

And in the North Atlantic, where ocean temperatures have soared, storms like Lee have had a field day.

According to NOAA research meteorologist John Kaplan, Lee’s wind speeds increased to 85 mph (137 km/h) in 24 hours, the third fastest cyclone in terms of intensity ever recorded in the Atlantic Ocean.

“There is no doubt that the exceptionally warm seawater we see bears human traces,” Kossin said. “Add to this the warming effects of El Niño this year and we have a recipe that can break many temperature records.”

Kossin found this to be particularly true in the eastern North Pacific, where warming due to an increasing El Niño phenomenon is strongest. “Jova is right in the middle and the warm water has certainly driven rapid intensification,” he added.

One thing is certain: as the world’s oceans continue to warm, experts say the frequency with which these large-scale storms can occur and intensify will only increase.