Warming Won't Drive More Hurricanes, Study Says

Aug. 4, 2008 -- The question of whether global warming is affecting hurricanes that form over the Atlantic Ocean -- and if so, how -- has sparked much debate in recent years. Climatologists believe that rising ocean temperatures can lead to stronger hurricanes, but the jury is still out on whether the storms will form more often in a warmer world.

A new study strengthens the argument that they won't.

Hurricane frequency has increased at a rate of about six storms per century since 1965, when weather satellites began keeping close watch over the Atlantic. Measurements are sketchy before then, and before the first storm reconnaissance flight in 1944 they're even worse -- the only source of information being ships' log entries.

When the record is extended back to include 1878-1900, however, storms appear to be on a slower rise, about 3.8 per century.

To correct for inaccuracies in the record before 1965, Gabriel Vecchi and Thomas Knutson of the National Ocean and Atmospheric Administration in Princeton, N.J., performed a thought experiment: What if modern-day storms had occurred back then? How many storms would ships traveling the Atlantic have simply sailed past without noticing?

When the researchers superimposed known storm tracks from 1965 onward over ship tracks between 1878 and 1965, they found the ships indeed missed many storms.