TAMPA, Fla. (WFLA) — Hurricane season is less than three weeks away and there’s new research into how hurricanes are changing in a warmer world.
The authors of paper published in late April used computer models to simulate how the risk of being hit by an intense hurricane will change during the next three decades.
The results are alarming.
Max Defender 8’s Jeff Berardelli spoke to the lead author of the study, Dr. Nadia Bloemendaal, from Free University of Amsterdam, about her results.
“In most places the probability of experiencing a severe tropical cyclone condition, I’m talking about category 3 wind speeds or up, more than doubles compared to the 1980-2017 climate conditions,” Bloemendaal said.
To reach these results her team used a statistical model called STORM to generate 10,000 years of synthetic (computer generated) tropical cyclones under the climate conditions from 1980–2017. To check the technique’s accuracy they verified that the distribution of tropical cyclones generated, in terms of number, intensity and geography, were approximately the same as the historical record.
Her team then extended that technique into the warmer present and future (2015 to 2050) conditions. To ensure balance, they used an ensemble of four high-resolution climate models. Generally speaking, the more computer models used and the more times the models are run, the more balanced and accurate the results.
Using those models, they derived high-resolution (10-km) maps, which plotted the return periods of intense wind speeds up to 1,000 years out. This helped them to assess the local-scale change in the reoccurrence 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 so fast in parts of New Jersey, it was said to be a once-in-1,000-years-event. Meaning that statistically speaking, if you lived in the same city in New Jersey for 1000 years, you should only expect to experience a rain rate that intense once every 1000 years.
Dr. Bloemendaal said the scale of the changes globally were very significant, showing that most places saw a large increase in the risk of being hit by a intense hurricane — more than doubling in most areas.
Interestingly, the Gulf of Mexico was one of the few places where the increase in intense storms was not very substantial.
Dr. Bloemendaal explained that the reason her study does not show a large change in the Gulf of Mexico is that her study projects a slight decrease in the overall number of storms in the Gulf, due to more atmospheric stability. This decrease in number is offset by the fact that the storms that do form are as intense, or even more intense. The result is not much change in the Gulf of Mexico, as opposed to what is projected globally.
When asked if this global increase in intense storms could be due to natural variability, and perhaps not climate change, Bloemendaal said, “There is of course a chance there is a bit of natural variability in there, but the bulk of the change really comes from climate change — the oceans warming. That is what we see in our model as well. The intensity has a very strong link with sea surface temperatures and when those temperatures increase the intensity will also go up.”
Globally, sea surface temperatures have risen about 2 degrees Fahrenheit since 1900.
Dr. Bloemendaal said the lesson from her research is that sturdier building codes are needed to survive a future with more intense hurricanes.