As soon as a hurricane reaches shore, its intensity begins to wane because it’s cut off from its power source: the ocean. But the pace at which a hurricane loses its force is changing because of global warming, according to a new report.
The report, published Wednesday in the science journal Nature, found that hurricanes in general are more likely to maintain their strength for longer, an evolution that will likely lead to more destructive outcomes.
The researchers looked at 71 hurricanes that made landfall in the North Atlantic between 1967 and 2018. They found that, 50 years ago, hurricanes lost roughly 75% of their intensity within the first 24 hours of making landfall. Today, hurricanes lose only about half of their energy within the first 24 hours.
That means that they’re packing more of a punch as they linger on land and meander through farmland, towns, and cities, lashing communities with winds, and potentially destroying more infrastructure and causing more casualties, injuries, loss of livelihood, and displacement than storms did decades ago.
Hurricane experts who spoke with the New York Times said that the sample size is too small to draw definitive conclusions and that the hurricane models deployed could use some fine-tuning.
“It’s a hard problem,” Dr. Suzana Camargo, a hurricane researcher at the Lamont-Doherty Earth Observatory, told the New York Times. “The models have to capture a lot of things that are going on — the interaction with topography, for instance.”
“I don’t know if what they did in the model is the best way to represent landfalling hurricanes,” Dr. Camargo added. “But at least in this model, it seems to agree with their idea.”
Camargo added that the new study opens up promising avenues for further investigation and is consistent with past research, including studies she herself has led.
Last year, a team of researchers at the Lamont-Doherty Earth Observatory published a study showing that hurricanes produce more rainfall because of warming ocean temperatures. As ocean water heats up, hurricanes suck more of it up and grow larger as a result. This then leads to more precipitation, a dynamic that was on full display with the landfall of Hurricane Harvey in 2017, which dumped a record-breaking 60.58 inches of rain on the greater Houston area.
Scientists have long suspected that hurricanes get supercharged by climate change because of higher temperatures and rising sea levels that give storms more water to throw around.
Some researchers believe that a new “Category 6” designation for super hurricanes will be needed in the years ahead if hurricanes keep growing in size and intensity.
No matter what, coastal regions will have to brace for an increasingly hostile future. Storms that occurred once every 100 years could soon be developing annually.
The most effective way to limit the destructive potential of hurricanes is to reduce the greenhouse gas emissions that heat up the atmosphere. The vast majority of the additional heat trapped in the air by gases like carbon dioxide and methane gets absorbed by the ocean, which leads to stronger storms and a whole host of other problems.
Countries also have to invest in adaptation measures such as more resilient infrastructure and wetland and coastal restoration projects, and even “managed retreats” away from the ocean. Some cities, such as Jakarta, have gone this route, calculating that it’s cheaper to relocate the entire city to another part of the country than to pay for growing environmental costs.