Tropical Cyclones May Drastically Increase in Frequency and Intensity as Climate Changes

The climate is changing--and not for the better when it comes to major storms and hurricanes. MIT scientists have revealed that the coming century may produce stronger and more frequent storms as the planet warms, creating the potential for hurricanes like Katrina.

For the past 40 years, the frequency and intensity of tropical cyclones has remained relatively stable. Approximately 90 of these storms spin across the world each year, causing their share of damages to coastlines. Over this time, these storms have remained the same in terms of intensity and maximum wind speed. Yet these new findings hint at a more tempestuous future.

In order to examine how the changing climate and greenhouse emissions might affect these storms, researchers employed several models. They simulated cyclones at both the global and local scales, embedding a high-resolution, local storm model within six climate models from the IPCC. The local storm model simulated the development of tropical cyclones, based on regional temperatures and large-scale atmospheric flow, at a resolution that increases as a storm intensifies. This allowed the model to resolve a storm's eyewall, the ring of thunderstorms circling the eye of a storm where the most severe weather occurs.

For each six models, the researchers simulated 600 storms every year from 1950 to 2005, using weather data from historical records. They then ran the models forward in time, simulating tropical cyclone development through 2100.

So what did they find? It turns out that the frequency of these storms will increase by 10 to 40 percent by 2100, assuming that greenhouse gas emissions continue to increase. In addition, the intensity of the storms could potentially increase by as much as 45 percent. The cyclones that make landfall would be as much as 55 percent more intense.

"Having a warmer tropical Pacific, especially in the central Pacific, makes the overall atmosphere more like those in El Niño events," said Kevin Trenberth, a scientist at the National Center for Atmospheric Research, who was not involved in the study in a news release. "Places like Hawaii and Tahiti and Fiji would likely be more in jeopardy under these scenarios."

The findings have enormous implications for the future of coastal communities in the Pacific. They reveal that in the future, communities will have to employ stronger preventative measures in order to keep storm damage to a minimum.

The findings are published in the journal Proceedings of the National Academy of Sciences.