Fast Facts

DOD’s global property holdings are worth nearly $1.2 trillion. Since 2010, DOD has identified climate change as a threat to its operations and installations.

We found that DOD's preliminary assessment of extreme weather and climate change effects at installations relied on past experience rather than an analysis of future vulnerabilities based on climate projections. Also, DOD’s designs for new construction at facilities generally did not consider climate projections, because DOD lacks guidance on how to do so.

We made 8 recommendations, including that DOD issue guidance on incorporating climate projections into facilities project designs.

Photo of cars partially submerged in flood waters

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Highlights

What GAO Found

Department of Defense (DOD) installations have not consistently assessed risks from extreme weather and climate change effects or consistently used projections to anticipate future climate conditions. For example, DOD's 2018 preliminary assessment of extreme weather and climate effects at installations was based on the installations' reported past experiences with extreme weather rather than an analysis of future vulnerabilities based on climate projections. Fifteen of the 23 installations GAO visited or contacted had considered some extreme weather and climate change effects in their plans as required by DOD guidance, but 8 had not. For example, Fort Irwin, California, worked with the U.S. Army Corps of Engineers to improve stormwater drainage after intense flash flooding caused significant damage to base infrastructure. By contrast, Joint Base Pearl Harbor-Hickam, Hawaii, did not include such considerations in its plans, although it is located in an area subject to tropical storms and where further sea level rise is anticipated.

Flooding at Naval Station Norfolk, Virginia

Flooding at Naval Station Norfolk, Virginia

GAO also found that most of the installations had not used climate projections, because they lack guidance on how to incorporate projections into their master plans. Not assessing risks or using climate projections in installation planning may expose DOD facilities to greater-than-anticipated damage or degradation as a result of extreme weather or climate-related effects.

Eleven of the 23 installations we reviewed had designed one or more individual facilities projects to increase the resilience of the facilities to extreme weather and climate change effects. However, project designs generally did not consider climate projections, according to installation officials. These officials told us that DOD lacks guidance on how to use climate projections that involve multiple future scenarios and different time periods. Until DOD updates its facilities design standards to require installations to consider climate projections in project designs, identify authoritative sources for them to use, and provide guidance on how to use projections, installation project designers may continue to exclude consideration of climate projections from facilities project designs, potentially making investments that are planned without consideration of climate-related risks.

Why GAO Did This Study

DOD manages a global real-estate portfolio with an almost $1.2 trillion estimated replacement value. Since 2010, DOD has identified climate change as a threat to its operations and installations. In January 2019, DOD stated that the effects of a changing climate are a national security issue with potential impacts to the department's missions, operational plans, and installations. GAO was asked to assess DOD's progress in developing a means to account for potentially damaging weather in its facilities project designs.

GAO examined the extent to which DOD has taken steps to incorporate resilience to extreme weather and climate change effects into (1) selected installation master plans and related planning documents, and (2) selected individual installation facilities projects.

GAO reviewed DOD documents related to increasing climate resilience, conducting installation master planning, and designing facilities projects. GAO visited or contacted a non-generalizable sample of 23 installations that had been associated with one or more climate vulnerabilities.

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Recommendations

GAO is making eight recommendations, including that the military departments work together to update master planning criteria to require an assessment of extreme weather and climate change risks and to incorporate DOD guidance on the use of climate projections into facilities design standards. GAO also recommends that DOD issue guidance on incorporating climate projections into installation master planning and facilities project designs. DOD concurred with all eight of GAO's recommendations.

Recommendations for Executive Action

Agency Affected Recommendation Status
Department of the Army The Secretary of the Army should ensure that the Chief of Engineers and Commanding General of the U.S. Army Corps of Engineers works with the Assistant Secretary of Defense for Sustainment; the Chief of Civil Engineers and Commander, Naval Facilities Engineering Command; and the Director of the Air Force Civil Engineer Center to update the Unified Facilities Criteria standard on installation master planning to require that master plans include (1) an assessment of the risks from extreme weather and climate change effects that are specific to the installation and (2) plans to address those risks as appropriate. (Recommendation 1)
Closed - Implemented
DOD concurred with this recommendation. In October 2019, the military departments implemented this recommendation by updating the Unified Facilities Criteria document for installation master planning to require that each installation identify and assess the risks to the installation from the effects of extreme weather and climate change, and develop plans to address those risks as appropriate.
Department of the Navy The Secretary of the Navy should ensure that the Chief of Civil Engineers and Commander, Naval Facilities Engineering Command works with the Assistant Secretary of Defense for Sustainment, the Chief of Engineers and Commanding General of the U.S. Army Corps of Engineers, and the Director of the Air Force Civil Engineer Center to update the Unified Facilities Criteria standard on installation master planning to require that master plans include (1) an assessment of the risks from extreme weather and climate change effects that are specific to the installation and (2) plans to address those risks as appropriate. (Recommendation 2)
Closed - Implemented
DOD concurred with this recommendation. In October 2019, the military departments implemented this recommendation by updating the Unified Facilities Criteria document for installation master planning to require that each installation identify and assess the risks to the installation from the effects of extreme weather and climate change, and develop plans to address those risks as appropriate.
Department of the Air Force The Secretary of the Air Force should ensure that the Director of the Air Force Civil Engineer Center works with the Assistant Secretary of Defense for Sustainment; the Chief of Engineers and Commanding General of the U.S. Army Corps of Engineers; and the Chief of Civil Engineers and Commander, Naval Facilities Engineering Command to update the Unified Facilities Criteria standard on installation master planning to require that master plans include (1) an assessment of the risks from extreme weather and climate change effects that are specific to the installation and (2) plans to address those risks as appropriate. (Recommendation 3)
Closed - Implemented
DOD concurred with this recommendation. In October 2019, the military departments implemented this recommendation by updating the Unified Facilities Criteria document for installation master planning to require that each installation identify and assess the risks to the installation from the effects of extreme weather and climate change, and develop plans to address those risks as appropriate.
Department of Defense The Secretary of Defense should issue guidance on incorporating climate projections into installation master planning, including—at a minimum—what sources of climate projections to use, how to use projections involving multiple future scenarios, and what future time periods to consider. (Recommendation 4)
Closed - Implemented
DOD concurred with this recommendation and stated that it is in the process of developing guidance to incorporate projections for sea level change into DOD's Unified Facilities Criteria standard for installation master planning, using a DOD-vetted source of data. DOD also stated that it will continue to tailor additional sources of climate projections data to other planning requirements and integrate these into departmental criteria as appropriate. In February 2020, the Under Secretary of Defense for Acquisition and Sustainment issued a memorandum which directed the use of DOD-provided sea level change projections in installation master planning and provided guidance on how to do so. In March 2021, DOD stated that it remains the department's goal to incorporate additional climate projection data into installation planning, but that such actions are not anticipated in the near term or by any certain date in the future. DOD's action to incorporate sea level change projections into installation master planning met the intent of our recommendation and we are hopeful that DOD will follow through on its intention to incorporate additional climate change projections into installation master planning.
Department of Defense The Secretary of Defense should issue guidance on incorporating climate projections into facilities project designs, including—at a minimum—what sources of climate projections to use, how to use projections involving multiple future scenarios, and what future time periods to consider. (Recommendation 5)
Closed - Implemented
DOD concurred with this recommendation and stated that it was in the process of developing guidance to incorporate projections for sea level change into Unified Facilities Criteria for facilities design, using a DOD-vetted source of data. DOD also stated that it would continue to tailor additional sources of climate projection data to other engineering requirements and integrate these projections into its criteria as appropriate. In February 2020, the Under Secretary of Defense for Acquisition and Sustainment issued a memorandum directing the use of sea level change projections in the facilities design process and provided guidance on how to do so. In March 2021, DOD stated that it remains the department's goal to incorporate additional climate projections data into the facilities design process, but that such actions are not anticipated in the near term or by any certain date in the future. DOD's action to incorporate sea level change projections into facilities designs met the intent of our recommendation, and we are hopeful that DOD will follow through on its intention to incorporate additional climate change projections into the facilities design process.
Department of the Army The Secretary of the Army should ensure that the Chief of Engineers and Commanding General of the U.S. Army Corps of Engineers works with the Assistant Secretary of Defense for Sustainment; the Chief of Civil Engineers and Commander, Naval Facilities Engineering Command; and the Director of the Air Force Civil Engineer Center to update relevant Unified Facilities Criteria to require that installations consider climate projections in designing facilities projects and incorporate, as appropriate, DOD guidance on the use of climate projections in facilities project designs—including identification of authoritative sources of such projections, use of projections involving multiple future scenarios, and what future time periods to consider. (Recommendation 6)
Closed - Implemented
DOD concurred with this recommendation. In September 2020, the Army, working with the other military departments, updated the Unified Facilities Criteria guidance on Civil Engineering to provide additional guidance on incorporating DOD-provide sea level change projections into facilities designs in accordance with the department's February 2020 memo directing the consideration of such projections in the facilities design process. By doing so the Army met the intent of our recommendation. DOD also stated in March 2021 that while it remains the department's goal to incorporate additional climate projections into facilities designs, it does not anticipate doing so at a certain date or in the near future. We are hopeful that DOD will follow through on its intention to incorporate additional climate projections into the facilities design process.
Department of the Navy The Secretary of the Navy should ensure that the Chief of Civil Engineers and Commander, Naval Facilities Engineering Command works with the Assistant Secretary of Defense for Sustainment, the Chief of Engineers and Commanding General of the U.S. Army Corps of Engineers, and the Director of the Air Force Civil Engineer Center to update relevant Unified Facilities Criteria to require that installations consider climate projections in designing facilities projects and incorporate, as appropriate, DOD guidance on the use of climate projections in facilities project designs—including identification of authoritative sources of such projections, use of projections involving multiple future scenarios, and what future time periods to consider. (Recommendation 7)
Closed - Implemented
DOD concurred with this recommendation. In September 2020, the Navy, working with the other military departments, updated the Unified Facilities Criteria guidance on Civil Engineering to provide additional guidance on incorporating DOD-provide sea level change projections into facilities designs in accordance with the department's February 2020 memo directing the consideration of such projections in the facilities design process. By doing so the Navy met the intent of our recommendation. DOD also stated in March 2021 that while it remains the department's goal to incorporate additional climate projections into facilities designs, it does not anticipate doing so at a certain date or in the near future. We are hopeful that DOD will follow through on its intention to incorporate additional climate projections into the facilities design process.
Department of the Air Force The Secretary of the Air Force should ensure that the Director of the Air Force Civil Engineer Center works with the Assistant Secretary of Defense for Sustainment; the Chief of Engineers and Commanding General of the U.S. Army Corps of Engineers; and the Chief of Civil Engineers and Commander, Naval Facilities Engineering Command to update relevant Unified Facilities Criteria to require that installations consider climate projections in designing facilities projects and incorporate, as appropriate, DOD guidance on the use of climate projections in facilities project designs—including identification of authoritative sources of such projections, use of projections involving multiple future scenarios, and what future time periods to consider. (Recommendation 8)
Closed - Implemented
DOD concurred with this recommendation. In September 2020, the Air Force, working with the other military departments, updated the Unified Facilities Criteria guidance on Civil Engineering to provide additional guidance on incorporating DOD-provide sea level change projections into facilities designs in accordance with the department's February 2020 memo directing the consideration of such projections in the facilities design process. By doing so the Air Force met the intent of our recommendation. DOD also stated in March 2021 that while it remains the department's goal to incorporate additional climate projections into facilities designs, it does not anticipate doing so at a certain date or in the near future. We are hopeful that DOD will follow through on its intention to incorporate additional climate projections into the facilities design process.

Full Report

GAO Contacts