Climate change boosting hurricane intensity

The fewer but powerful hurricanes that the world has witnessed in recent years are likely due to the warming climate, a new study says.

"We are seeing fewer hurricanes, but the ones we do see are more intense," said one of the researchers, professor Jim Elsner from Florida State University in the US.

"When one comes, all hell can break loose," Elsner said.

The researchers projected that over the past 30 years, storm speeds have increased on average by 1.3 metres per second -- or 4.8 km per hour -- and there were 6.1 fewer storms than there would have been if land and water temperatures had remained constant.

"It is basically a tradeoff between frequency and intensity," Elsner said.

Prior to this research, there had been some discussions among scientists about how warmer ocean temperatures affected the intensity of a hurricane.

In the current study, the researchers wanted to further explore that concept as well as the number of storms that occurred each year.

Hurricanes can form when ocean waters are 79 degrees Fahrenheit (26.1 degrees Celsius) or more. As the warm water evaporates, it provides the energy a storm needs to become a hurricane.

Higher temperatures mean higher levels of energy, which would ultimately affect wind speed.

The researchers said the yearly temperatures can also be a good indicator of what's yet to come in a given storm season.

"In a warmer year, stronger but fewer tropical cyclones are likely to occur," said corresponding author Namyoung Kang, deputy director of the National Typhoon Centre in South Korea.

"In a colder year, on the other hand, weaker but more tropical cyclones (are likely to occur)," Kang said.

The study was published in the journal Nature Climate Change.