Doyle Rice

USA TODAY

Corrections & Clarifications: An earlier version of this story misstated the location of Langley Air Force Base. The base is located in Hampton, Va.​

Military bases along the East and Gulf Coast are at risk of losing large chunks of land as rising sea levels from man-made climate change swamp installations from New Hampshire to Florida.

The onslaught of water will come from both tidal flooding and hurricane storm surge and could cause a 2,600% increase in the number of annual flooding events on several bases in the U.S. in coming decades, according to a report released Wednesday by the Union of Concerned Scientists.

Sea level increases — already up 8 inches globally since 1880 — are the result of warming temperatures and ice melt caused by heat-trapping greenhouse gases. The phenomenon, which scientists say is primarily caused by global warming, doesn't occur evenly worldwide. The East and Gulf Coasts in the U.S. experience some of the fastest rates of sea-level rise, according to the National Oceanic and Atmospheric Administration.

The Union of Concerned Scientists found that by 2050, half of the 18 East and Gulf Coast military installations it analyzed would experience 270 or more flood events per year — up from just 10 events annually today.

Four bases in Florida, Virginia and South Carolina could lose 20% or more of their land in the same time period, said Erika Spanger-Siegfried, lead author of the report, which used peer-reviewed scientific research and other projections to make the predictions.

"Military bases and personnel protect the country, often providing rescue services in dangerous floods and other natural disasters," the report states. "Our defense leadership has a special responsibility to protect the sites that hundreds of thousands of Americans depend on for their livelihoods and millions depend on for national security."

Over the past century, sea level climbed a foot or more in some U.S. cities due to ocean currents and land subsidence, a gradual settling or sudden sinking of the Earth's surface due to underground movement of soil and dirt.

Scientists don't know exactly how much higher the waters will climb, but many project global sea level will rise about 1 foot to slightly more than 3 feet by 2100, according to the most recent assessment report by the United Nations' Intergovernmental Panel on Climate Change. NOAA predicts sea level could rise higher, by as much as 6½ feet, by century's end.

“The Pentagon knows it has a problem, and some bases are already making an effort to reduce their exposure,” Spanger-Siegfried said. Langley Air Force base near Hampton, Va., for example, is raising electrical equipment and installing flood barriers and pumps, among other efforts, she added.

Not all of the bases the environmental group analyzed responded to the report, but of those that did, Spanger-Siegfried said she was "surprised how much some places were so acutely aware of the issues."

“But there’s a big gap between what’s being done and what’s needed," she added.

Air Force Lt. Col. Eric Badger. a spokesman for the Pentagon, said the Defense Department was aware of the report but had no immediate comment.