Pearl Harbor, forever synonymous with the events of Dec. 7, 1941, today faces a new threat: rising seas.

Joint Base Pearl Harbor-Hickam was called out in a new federal Government Accountability Office report on Pentagon climate preparedness for failure to consider changing long-term conditions in facility planning. Sea levels could rise more than 3 feet by 2065 at the home of the U.S. Pacific Fleet, and storms might grow more intense.

Joint Base Pearl Harbor-Hickam did not consider extreme weather and climate change effects in its most recent master plan even though it is in an area that has been subject to tropical storms, according to the GAO report released Wednesday.

The lowest elevation point on the Navy’s side of the joint Navy-Air Force base, Naval Station Pearl Harbor, is 0.6 foot below sea level. The installation stated that it plans to incorporate the effects of climate change into the next update to its facilities master plan, according to the GAO report.

The report said Pearl Harbor Naval Shipyard also did not consider extreme weather or climate change effects in its most recent master plan, although it shares the same weather and climate conditions as Joint Base Pearl Harbor- Hickam, where it’s located.

The Hawaii facilities were not alone.

The GAO studied 23 domestic military facilities to help understand risks facing the Department of Defense’s $1.2 trillion real estate portfolio. Researchers found that eight of the installations, including the two at Pearl Harbor, hadn’t yet made climate-risk analysis a regular part of infrastructure work, while the other 15 had begun to follow recent Pentagon guidance.

Only one project among the 23 installations surveyed by the GAO took climate projections into account at the design phase.

Naval Base San Diego last year was planning to replace a pier. A contractor involved in the work brought to officials’ attention sea-level-rise projections for the expected 75-year life span of the pier. As a result, the Navy raised the height of the structure by a foot.

Other installations have included some weather and climate analysis in their master plans, which are decade-ahead or longer overviews of site infrastructure development:

>> Virginia’s Langley Air Force Base, which sustained damage during Hurricane Isabel in 2003, afterward required new structures to be built at least 10.5 feet above sea level, or a foot higher than the 500-year flood plain.

>> The 611th Civil Engineer Squadron, at Joint Base Elmendorf-Richardson in Alaska, teamed up with local university experts to model coastal erosion occurring on the North Slope, where the base maintained two radar sites.

>> Officials at Camp Pen­dleton, Calif., last year added coastline protections while building a new aircraft landing area. Accelerated erosion was endangering an environment used for amphibious assault training.

The GAO has watched the Pentagon’s climate-planning work for several years, with an increasing focus on possible military financial risk. The report chronicles some of the auditor’s and the defense agency’s challenges since then, such as the DOD’s slow response to requests that extreme-weather damage be cataloged and shared.

“There is substantial budgetary risk resulting from weather effects associated with climate change, and these types of repairs are neither budgeted for nor clearly represented in the federal budget process,” the GAO wrote.

The agency made eight recommendations, among them that the armed forces update guidelines to include climate-risk analysis in master plans and guidance on how installations can make use of climate projections when they prepare such plans.

A Pentagon response included in the GAO report concurred with all the recommendations.