A new Pentagon report identifies military facilities vulnerable to climate change, documenting the effect of flooding, drought and extreme temperatures at installations across the United States.
The assessment is based on the first survey of climate-related events at U.S. training bases, airfields and other military facilities.
"If extreme weather makes our critical facilities unusable or necessitate costly or manpower-
intensive workarounds, that is an unacceptable impact," said the report from the Pentagon's assistant secretary for energy installations and the environment.
The survey, which was conducted under the Obama administration and submitted to Congress on Friday, signals concern among defense officials about the challenges that climate change might pose for the U.S. military.
"The idea was to try and figure out . . . how climate effects were impacting the installations and in what way," said John Conger, who served as a senior Pentagon official under the Obama administration and was among the officials who initiated the survey.
Officials suspected that flooding was taking a toll on coastal installations such as Naval Station Norfolk, and that drought and wildfire were affecting inland facilities. But they needed reporting from those locations to have a clear nationwide picture.
According to the survey, which was rolled out to military sites in 2014, the most frequent problems named were drought, wind and non-storm-surge-related flooding. Nearly half of the sites reported no impact.
The report provides examples from the facilities, including the U.S. Naval Academy in Annapolis, Md., which has been subject to storm surge flooding and hurricane damage, and the Cape Lisburne Long Range Radar Station in Alaska, where extreme weather and "wave action" have worn down a key sea wall.
It also includes the U.S. Air Force Academy and Peterson Air Force Base in Colorado. Both have been affected by wildfires.
In a few instances, the report cites weather-related problems severe enough to "cripple the operational mission of a base," such as Homestead Air Reserve Base in Florida after Hurricane Andrew in 1992 and Langley Air Force Base in Virginia after Hurricane Isabel in 2003.
Conger said the survey was intended in part to act as a baseline for future assessments.
"It's in the Defense Department's interest to make investment decisions in a wise way and to make sure it doesn't have damage to those investments," he said.
Conger said he was surprised by the widespread wind damage to power lines on bases.
The survey did not address the financial cost of climate-related phenomena on military facilities or the possible impact on defense missions.
The Defense Department produced a comprehensive "road map" for climate change during the Obama administration, but it is not clear what actions will be taken under the current administration.
President Trump has questioned the science behind climate change, and his recent national defense and security strategies did not mention the issue. But numerous senior defense officials, including Defense Secretary Jim Mattis, have publicly stated that climate change has affected U.S. security.
The Pentagon is required to prepare a report for Congress in coming months that would lay out which military sites are vulnerable to "rising sea tides, increased flooding, drought, desertification, wildfires, thawing permafrost." It also would address whether the military is facing increased requests for disaster and humanitarian assistance.
"This is only the first step," Conger said of the new survey. "Nobody should assume that this is the end of the story."