ORLANDO, Fla. – Is global warming to blame for the last two horrific hurricane seasons?

Yes, says Judith A. Curry, a professor of atmospheric sciences at the Georgia Institute of Technology. Her argument: Worldwide sea surface temperatures have increased by about 1 degree since 1970, resulting in about 50o/o more tropical storm activity than normal.

No, counters James J. O’Brien, a professor of meteorology and oceanography at Florida State University. His point: Since 1850, the Earth has undergone numerous warming and cooling cycles, and there has been no dis­ tinct trend in the overall intensity of hurricane seasons.

Friday’s debate by the two climate experts at the National Hurricane Conference took on urgency in light of last season, which produced a record 28 storms, 15 of them hurricanes.

Curry said greenhouse warming, created by gases trapped in the atmosphere, had resulted in a sharp increase in tropical activity, particularly in the last decade. Since 1995, 166 tropical storms – including 112 hurricanes, 28 of them Category 4 and 5 systems – have been spawned in the abnormally warm waters of the Atlantic basin.

Although scientists say a natural cycle of ocean warming is responsible for that rise in activity, Curry noted that the peak period of the previous cycle, from 1945 to 1955, saw considerably fewer systems: 115 tropical storms, including 74 hurricanes, 19 of them Category 4 and 5.