Does climate change make hurricanes worse? – 08/31/2023 – Environment

Scientists have been warning of the impact of climate change on hurricanes like Idalia, which rapidly strengthened in the Gulf of Mexico before making landfall in Florida on Wednesday.

Read below what is known about the effects of the climate crisis on these natural phenomena.

El Niño and warmer oceans

In May, the US National Oceanic and Atmospheric Administration (NOAA) anticipated an “almost normal” Atlantic hurricane season.

That prediction was based largely on the existence of the El Niño meteorological phenomenon, which curbs the formation of hurricanes by increasing the vertical circulation of the wind, which causes the descent of cold air.

The entry of this “dry and less energetic” air into the heart of a tropical cyclone “prevents it from strengthening,” Allison Wing, a scientist at Florida State University, told AFP.

But in August, the agency adjusted its forecasts upwards, announcing that the season would be “above normal” based on ocean and weather conditions. He explained that “record temperatures on the surface of the Atlantic” would likely offset the effects of El Niño for hurricanes.

“In terms of seasonal forecasts, it’s a tricky year because we have these two contradictory factors,” added Wing.

more intense storms

On July 24, a buoy in southernmost Florida registered a temperature of 38.4°C, closer to that of a hot tub than that of an ocean, a possible world record.

“Warm water, both on the ocean’s surface and deep below, acts as a fuel that intensifies tropical storms and hurricanes,” said Michael Mann, a climatologist at the University of Pennsylvania. “This allows them to get stronger faster and reach higher peak power.”

Hurricanes require a number of conditions to form, but when they do, ocean heat allows them to generate stronger winds and higher tides.

“We could say that climate change is a crapshoot,” added Wing. “Very different scenarios are still possible for each storm, but the likelihood of a very intense storm is higher.”

Climate change could also increase the amount of rain hurricanes bring, according to Andrew Kruczkiewicz, a researcher at Columbia University’s Climate and Society Research Institute.

“The warmer the atmosphere, the greater the water absorption capacity”, which could mean more rain, said the expert.

People who fled inland to escape a hurricane could also face extreme conditions, he added.

Rainfall during Hurricane Ian in September 2022 increased by at least 10% due to climate change, according to recent research.

Longer hurricane seasons

In addition to the intensity of the storms, their seasons seem to be getting longer and longer.

According to Mann, the period when ocean surface temperatures favor the formation of tropical storms starts earlier and ends later. This appears to be the case in both the Atlantic and the Bay of Bengal in Asia.

Much research indicates that climate change makes hurricanes more dangerous, but the effect on frequency is more uncertain and further studies are needed to understand it.