Researchers at the University of Hawaii at Manoa have discovered that hurricanes across the globe have increased in speed over the past several decades, a possible result of climate change and other factors.

While the average movement speed has increased globally since 1982, the study found that hurricanes in our neighborhood of the Pacific have slowed down.

The new study, which examined thousands of tropical cyclones from 1982 to 2017, is the first to show that hurricanes are actually increasing in speed overall, by about 0.2 mph per decade.

The research published in the journal Environmental Research Letters contradicts the conclusion of a 2018 study that found that hurricanes were slowing.

Pao-Shin Chu, a UH-Manoa atmospheric sciences professor, said it turns out the widely cited 2018 study was flawed because it relied on early hurricane data that was less reliable.

Chu said only modern post-satellite era data was examined in the new study, led by Sung-Hun Kim, a postdoctoral researcher in the UH-Manoa School of Ocean and Earth Science and Technology.

The researchers assessed the frequency and locations of storms and trends in tropical cyclone movement speed — how quickly a storm moves forward — globally and regionally in each ocean basin.

They also determined the North Atlantic has seen a greater number of hurricanes and that tropical cyclone activity has moved closer to the poles in both the Pacific and Atlantic oceans.

Previous studies have blamed human-induced climate change for the rise in higher-latitude hurricanes.

Chu said the largest hurricane speed increases were seen in the western North Pacific, the South Pacific and the Indian oceans. Higher speeds were also seen in the North Atlantic as a greater number of hurricanes ventured into higher latitudes, where cyclones are known to move at faster speeds.

Chu said faster-moving hurricanes present a danger to coastal communities and emergency managers because there is less time to prepare for evacuation and execute other safety measures.

It’s especially true for remote islands and areas of the globe that do not have the technology to effectively track hurricane movement, he said.

“If they can’t do that, it’s going to be a problem,” Chu said.

Increasing cyclone speeds were not seen uniformly in all ocean basins, however. In fact, there were slower speeds observed overall in the eastern North Pacific, an area that extends from the West Coast to Hawaii and the Central Pacific, to the International Date Line.

Chu, who also wears the hat of Hawaii state climatologist, said that because the eastern North Pacific generates so few cyclones per year on average, its contribution isn’t significant enough to affect the global mean.

Slower hurricanes, on the other hand, offer their own issues, including more rain, flooding, coastal inundation and more, he said.

“Slower storms may stay around longer and be more dangerous,” Chu said. “When they’re faster moving, they can catch you by surprise. It’s a different kind of danger.”

While the study didn’t look into the future, Chu said, the science is mixed on whether hurricane speeds will continue to accelerate.

“The general consensus is that we will see fewer tropical cyclones globally, but they will be stronger,” he said.

The researchers said they plan to continue to study the trends and links between climate variability and cyclone activity.