Climate change doubles likelihood of intense hurricanes, study finds

TAMPA, Fla. (WFLA) – Hurricane season is less than three weeks away and new research has been conducted on how hurricanes evolve in a warmer world.

The authors of a paper published at the end of April used computer models to simulate the evolution of the risk of being hit by an intense hurricane over the next three decades.

The results are alarming.

Max Defender 8’s Jeff Berardelli spoke with the study’s lead author, Dr Nadia Bloemendaalfrom the Free University of Amsterdam, about his results.

“In most locations, the likelihood of experiencing a severe tropical cyclone condition, I’m talking about Category 3 wind speeds or higher, more than doubles compared to 1980-2017 weather conditions,” Bloemendaal said.

A study in Science Advances reveals more intense tropical cyclones. Image credit: WFLA

To achieve these results, his team used a statistical model called STORM to generate 10,000 years of synthetic (computer-generated) tropical cyclones under climate conditions from 1980 to 2017. To verify the accuracy of the technique, they verified that the distribution of tropical cyclones generated, in terms of number, intensity and geography, was approximately the same as the historical record.

His team then extended this technique to present and future warmer conditions (2015 to 2050). To ensure balance, they used a set of four high-resolution climate models. In general, the more computer models are used and the more models are run, the more balanced and accurate the results.

Using these models, they derived high-resolution (10 km) maps, which plotted return periods of intense wind speeds up to 1,000 years. This helped them to assess the change at the local scale in the reappearance of certain intense wind speeds.

To better explain what a return period is, we can use Hurricane Ida as an example. The rain fell so hard and fast in parts of New Jersey that it would be a once-in-a-1,000-year event. This means that statistically speaking, if you’ve lived in the same New Jersey town for 1000 years, you should only expect to experience such an intense rainfall rate once every 1000 years.

Dr Bloemendaal said the magnitude of the changes globally was very large, showing that most places have seen a big increase in the risk of being hit by an intense hurricane – more than doubling in most areas .

Top left: Hurricane Andrew 1992. Top right: Hurricane Charley 2004. Bottom left: Hurricane Irma 2018. Bottom right: Hurricane Michael 2018. Image credit: NOAA

Interestingly, the Gulf of Mexico was one of the few places where the increase in intense storms was not very significant.

Dr. Bloemendaal explained that the reason his study does not show a significant change in the Gulf of Mexico is that his study predicts a slight decrease in the total number of storms in the Gulf, due to greater atmospheric stability. This decrease in numbers is compensated by the fact that the storms that form are just as intense, if not more intense. The result is not much change in the Gulf of Mexico, contrary to what is projected globally.

Asked if this global increase in intense storms could be due to natural variability, and maybe not climate change, Bloemendaal said: “There is of course a chance that there will be some natural variability there, but most of the change is really coming from climate change — the warming of the oceans. This is also what we see in our model. Intensity has a very strong link with sea surface temperatures and as these temperatures increase, intensity will also increase.

Globally, sea surface temperatures have risen about 2 degrees Fahrenheit since 1900.

The oceans have been warming since 1901. Image credit: Climate Central

Dr. Bloemendaal said the lesson of his research is that stronger building codes are needed to survive a future with more intense hurricanes.

Teresa H. Sadler