A nondescript metal box at the end of an unremarkable pier in Norfolk, Va. is one key to why the U.S. Navy is concerned about climate change.
For nine decades, the Sewells Point tide gauge or its ancestors have been recording the sea level off Pier 6 at Naval Station Norfolk.
The story it tells is clear. Between naturally sinking land and global warming driven sea level rise, the water is a half-meter higher than it was at the beginning of the last century.
That's creating problems at the world's largest naval base.
In rough weather, damaging surf slams against electrical, water and steam lines under the piers where the Navy docks its Atlantic fleet. High waves can keep sailors from getting to the ships. Even getting on base is getting harder as "nuisance flooding" becomes a regular problem, cutting off roads around the city of Norfolk.
"It's not going to stop us from accomplishing our mission. We're the military. We'll figure it out," said Capt. Dean VanderLey, commanding officer of Naval Facilities Engineering Command for the Mid-Atlantic region. "But it just makes things more difficult."
"The higher the sea level gets, the more we're going to have to deal with that," he adds. "I don't think we fully understand the scope of the problem. And we definitely don't fully understand the solution."
Hoax vs. threat multiplier
The commander-in-chief, President Donald Trump, has called global warming a hoax, although he now says there is "some connectivity" between human activity and climate change.
The Pentagon, on the other hand, takes the risks of climate change seriously.
Rising seas threaten coastal installations. Severe storms can cut off supply routes. Extreme heat limits training.
"The military has seen climate change as a problem since 2003, if not earlier," says retired Army Gen. Gerry Galloway, now with the Center for Climate and Security.
National security threats from climate change are included in eight defense and intelligence documents published before President Obama took office, according to the center.
"Climate change acts as a threat multiplier for instability in some of the most volatile regions of the world," a group of high-ranking former military officials wrote in a landmark 2007 report.
"Economic and environmental conditions in already fragile areas will further erode as food production declines, diseases increase, clean water becomes increasingly scarce, and large populations move in search of resources," the report continued.
These conditions "foster the conditions for internal conflicts, extremism and movement toward increased authoritarianism and radical ideologies."
Planning for the impacts accelerated under the Obama administration. In 2014, DOD published a "Climate Change Adaptation Roadmap" outlining risks and responses.
While the new president is a climate skeptic, his pick for secretary of defense acknowledges the threat.
Retired Marine Gen. James Mattis led the U.S. Joint Forces Command. The 2010 Joint Operating Environment report that he signed described climate change as "one of the 10 trends most likely to impact the Joint Force."
It notes the melting of the Arctic and the competition for newly available resources "is but one example of potential security challenges that did not exist in the past."
Eye to the future
Trump supports a strong military, and "I personally don't believe that the administration is going to do anything that's going to interfere with the military being prepared," Galloway says.
"Now, there will be fights over dollars," he adds, and who gets the resources will depend on the president's defense priorities.
At Naval Station Norfolk, they already are adapting to the realities they see coming. Newer piers are built higher, with the utility lines under a protected concrete deck.
"When we do construct facilities, we're doing that with an eye toward the future, as we always do," Capt. VanderLey says. "One of those things we see in the future is, potentially, sea level rise."
VanderLey stays away from the politics of climate change and how the new administration might affect adaptation plans.
"We're just trying to be good, smart engineers," he says. "And I can't imagine anyone's going to decide to stop being good, smart engineers.