Study: Warmer Fire Island more vulnerable to storms

The report said the parks studied are experiencing a rise in sea levels at least equal to the global average thanks to the warmer climate, and are especially vulnerable during storms.

The study by the Natural Resources Defense Council and the Rocky Mountain Climate Organization projected that without steps to lessen climate change, temperatures in the six parks it studied would increase by as much as 3.6 degrees on Fire Island by the decade ending 2060, and as little as 3.0 at Cape Hatteras, N.C., in that time period.

Fire Island showed the largest temperature increase, up 1.8 degrees in 2000-2001 from the annual average between 1961 and 1990, according to the report.

The smallest increase in that period was 0.8 degrees at both Cumberland Island National Seashore in Georgia and Assateague Island National Seashore in Maryland and Virginia, the report said.

The other seashore national parks studied -- Cape Cod in Massachusetts, Canaveral in Florida and Cape Hatteras and Cape Lookout in North Carolina -- ranged from 1.2 degrees hotter to 1.7 degrees hotter, the report said.

The parks had more than 11 million visitors who spent $566 million in 2010 and supported about 7,500 jobs, the report said, and people could be less likely to visit if temperatures become "intolerably hot."

"Human disruption of the climate is the greatest threat ever to America's national parks," the report said.