Navy Official Discusses Climate Change Investment Strategy

A number of recent strategic Defense Department documents have recognized that the changing climate may affect national security and military operations later in the century.

“One of the investments we're really going to have to think about in the next several decades is the impact of sea level rise on the Navy's infrastructure,” Titley said. “That includes our ports and piers in the continental United States, but we also need to think about bases we use in conjunction with our partners and allies overseas.”

As an example, Titley mentioned Diego Garcia, a small, low-lying island in the Indian Ocean that hosts a strategic airfield.

“The observations have shown us that through the 20th century, sea level rose by an average of two millimeters per year,” Titley said. “So that means over the course of the century, we had about 20 centimeters, or roughly eight inches, of sea level rise. The sea level rise we've seen in the first 10 years of the new century is already 50 percent greater than the average sea level rise in the 20th century.”

Titley explained that as the oceans get warmer, they expand and take up more space, causing the sea level to rise. In addition, the land-based ice that already is melting -- including mountain glaciers, the Greenland ice field, and even the western Antarctic ice sheet -- will add volume to the ocean. He acknowledged considerable uncertainty over the time line and extent of sea level rise, but he noted that leading climate scientists believe sea levels could rise as much as six feet by the end of the century.

Titley said the main goal of Task Force Climate Change is to ensure the Navy is not taken by strategic surprise, and he expressed satisfaction that climate change is being considered in strategic war games and limited objective experiments. He described these as “thinking exercises” that examine various strategic scenarios to determine how to handle them, to evaluate whether the assets are available to handle them, and to identify shortfalls.