Warming expected to cut Atlantic hurricane tally, but boost threat

Andrew Revkin

A new modeling study published in this week’s issue of Science projects a rise of about 30 percent in potential hurricane damage in the western Atlantic toward the end of the century as emissions of greenhouse gases rise. Although the overall number of storms in the region are expected to drop, the number of strong ones — those reaching Category 4 or 5 in the hurricane index — are expected to double from the number produced now, the study says. The projections are based on a midrange scenario for a rise in the heat-trapping emissions linked to global warming.

The two maps below, produced for the study by the Geophysical Fluid Dynamics Laboratory at Princeton, are based on a climate model comparing the production of strong hurricanes in conditions mimicking the current climate (basically, average climate conditions from 1980 to 2006) with hurricane production in conditions simulating those projected for the final two decades of the century.

It’s still early days in the effort to understand how hurricanes, which thrive or fade depending on local conditions, will fare in a globally warmed world. But the modeling exercise hints at factors that do seem to make the biggest difference. “What’s really important for Atlantic hurricane activity, what really gets things cranked up, is when the Atlantic warms relative to the rest of the tropics,” said Thomas Knutson, one of the paper’s authors and a climate researcher at the Geophysical Fluid Dynamics Laboratory. He said that is what has happened in the real world since 1980, as scientists witnessed a big rise in hurricanes’ energy.

The rest of the New York Times blog article is here.