As sea levels continue to rise and more intense storms continue to cause widespread damage across the United States, experts say climate change is likely to impact National Security concerns as well.

Ron Dole, an associate professor at Florida State University, says the Department of Defense has had a keen interest in the impacts of climate change— dating all the way back to World War II. Scientists, at the time, began collecting data from both the North and South Poles and saw they were getting warmer.

The US military cared about these temperature changes because the warming of the North Sea meant the Soviet Union could potentially move their Naval ships around the globe with more ease.

“Would the growing season suddenly be improved in the Soviet Union? Would their troops be a better fit? Could the North Sea be opened for a longer time? These were all questions defense officials started looking at,” Dole said.

“The definition of National Security suddenly shifted and broadened,” he added.

There are also current-day impacts of climate change on National Security.

John Conger, a senior advisor for the Council on Strategic Risk says rising sea levels and more intense storms are having direct impacts on military installations and military planning.

“As climate change proceeds, you’ll have installations built for certain weather and that’s changing, sea-level rise will yield more recurrent flooding. You can’t fly off a flooded runway,” Conger noted.

Conger also points to the broader geopolitical impacts climate change is already having: Helping to increase the impacts of war, migration and global conflict in general.

“It’s going to drive instability around the world. So in that context, they call climate change a threat multiplier, it makes bad situations worse.”