WASHINGTON: Climate scientist Michael Oppenheimer stood along the Hudson River and watched his research come to life as Hurricane Sandy blew through New York.

Just eight months earlier, the Princeton University professor reported that what used to be once-in-a-century devastating floods in New York City would soon happen every three to 20 years. He blamed global warming for pushing up sea levels and changing hurricane patterns.

New York “is now highly vulnerable to extreme hurricane-surge flooding,” he wrote.

For more than a dozen years, Oppenheimer and other climate scientists have been warning about the risk for big storms and serious flooding in New York. A 2000 federal report about global warming’s effect on the United States warned specifically of that possibility.

Still, they say it’s unfair to blame climate change for Sandy and the destruction it left behind. They cautioned that they cannot yet conclusively link a single storm to global warming, and any connection is not as clear and simple as environmental activists might contend.

“The ingredients of this storm seem a little bit cooked by climate change, but the overall storm is difficult to attribute to global warming,” Canada’s University of Victoria climate scientist Andrew Weaver said.

After years of disagreement, climate scientists and hurricane experts have concluded that as the climate warms, there will be fewer total hurricanes. But those storms that do develop will be stronger and wetter.

Sandy took an unprecedented sharp left turn into New Jersey. Usually storms keep heading north and turn east harmlessly out to sea. But a strong ridge of high pressure centered over Greenland blocked Sandy from going north or east, according to the National Hurricane Center.