Man-made Climate Change Causing Stronger Hurricanes

The increase in the intensity and duration of Atlantic hurricanes in recent decades is due to temperature increases in the atmosphere caused by global warming, and not by natural variations in ocean temperature, according to a new study.

Recent studies have linked rising sea surface temperatures, or SSTs, in the Atlantic Ocean to climate change caused by human activities. Warmer SST's means the ocean is capable of storing more energy--energy that is converted into wind power during tropical storms.

However, other scientists blame a decades-long natural variation in ocean temperature, called the Atlantic Multidecadal Oscillation, or AMO, for the rising SST trend.

Both camps agree that rising SSTs are contributing to increasing hurricane strength, but until now, the connection between air temperature and SST was unclear. Do rising atmospheric temperatures cause sea surface temperatures to rise? Or is it the other way around?

Now, James Elsner, director of the Hurricane Center at Florida State University, says he has broken the deadlock using a statistical test that determines causality. His conclusion: that a warming atmosphere is raising sea surface temperatures, causing hurricanes to become stronger.

Elsner's finding is detailed in the current issue of the journal Geophysical Letters.