Human beings are warming the oceans where hurricanes are born, scientists said Monday, and the storms are getting fiercer as a result.
A new study, based on computer modeling, links actions such as burning fossil fuels and cutting down forests to warmer sea surface temperatures in hurricane regions of the Atlantic and Pacific oceans.
The paper makes the final link between people’s activities and a recent increase in hurricane intensity, its authors argue.
“The work we’ve done kind of closes the loop here,” said Tom Wigley, a scientist with the National Center for Atmospheric Research in Boulder.
Wigley and several colleagues predict that hurricanes will continue to strengthen as people keep warming the oceans.
Other scientists were quick to refute the contention, turning the paper into the latest squall in a scientific tempest that is splitting the research community.
Between 1906 and 2005, sea surface temperatures in the Atlantic and Pacific regions where hurricanes form increased about one degree Fahrenheit.
Warm waters are one component in the formation and intensity of hurricanes and typhoons.
The new study found an 84 percent chance that greenhouse-gas emissions account for most of that sea temperature rise.
Nineteen international climate experts contributed to the work, which appears in the Proceedings of the National Academy of Sciences.
“This paper is a travesty,” said William Gray, a Colorado State University professor emeritus and noted hurricane forecaster.
Gray criticized the researchers for poorly defining regions of temperature increase and for making the link – during a news conference on the paper – between climate change and increased storm intensity.
In the past two years, researchers have published more than a dozen hurricane papers, some arguing that the storms have increased in intensity, others that cyclone activity swings up and down every few decades and we’re in a stormy period.
Kerry Emanuel, a climate researcher at the Massachusetts Institute of Technology in Cambridge is among those who see clear evidence that hurricanes are getting stronger, probably because of human activity.
“It’s controversial among weather forecasters. It’s not controversial among climate scientists,” Emanuel said.
“That’s not just the case,” said Chris Landsea, chief science and operations officer at the National Hurricane Center in Miami. Landsea praised the new paper for making a fairly clear link between global warming and warmer ocean temperatures.
“It’s a small advance in the field,” Landsea said, “but this really isn’t a hurricane paper.”
Staff writer Katy Human can be reached at 303-954-1910 or at khuman@denverpost.com.
