Climate Resilience: DOD Needs to Assess Risk and Provide Guidance on Use of Climate Projections in Installation Master Plans and Facilities Designs

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.

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.

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.

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.

The Department of Defense (DOD) manages a global real-estate portfolio  with an estimated replacement value of almost $1.2 trillion, including  installations in all regions of the continental United States, Alaska, and  Hawaii, as well as in foreign locations. These installations not only  provide services and support to servicemembers and their families, but  are critical to maintaining military readiness. Since 2010, DOD has  identified climate change as a threat to its operations and installations  and stated that the department needs to adapt its infrastructure to the  risks posed by climate change. In January 2019, DOD stated in a report  to Congress that the effects of a changing climate are a national security  issue with potential impacts to the department’s missions, operational  plans, and installations.

The effects of climate change, such as sea level rise, may damage  infrastructure and result in increased costs to the department. These  costs are projected to increase as extreme weather events become more  frequent and intense as a result of climate change—as observed and  projected by the U.S. Global Change Research Program and the National  Academies of Sciences, Engineering, and Medicine. According to the  U.S. Global Change Research Program’s Fourth National Climate  Assessment, the effects of climate change are already being felt in the  United States and are projected to intensify in the future. These effects  will include increases in the incidence of extreme high temperatures,  heavy precipitation events, high tide flooding events along the coastline,  and forest fires in the western continental United States and Alaska. The  assumption that current and future climate conditions will resemble those  of the recent past is no longer valid, according to the report. For example,  sea levels are expected to continue to rise along almost all U.S.  coastlines.

We and others, such as the National Academies of Sciences,  Engineering, and Medicine, have therefore recommended enhancing  climate resilience as one strategy to help limit the federal government’s  fiscal exposure. Enhancing climate resilience means being able to plan  and prepare for, absorb, recover from, and more successfully adapt to  climate-related impacts, such as those identified by the U.S. Global  Change Research Program in the 2018 Fourth National Climate  Assessment. Examples of resilience measures to protect infrastructure  include raising river or coastal dikes to reduce the risks to infrastructure  from sea level rise, building higher bridges, and increasing the capacity of  stormwater systems. Enhancing climate resilience can add additional  costs up front, but could also reduce potential future costs incurred as a  result of damage from climate-related events.

As a result of the significant risks posed by climate change, in February  2013, we placed Limiting the Federal Government’s Fiscal Exposure by  Better Managing Climate Change Risks on our High-Risk List. As part of  our work in this high-risk area, in 2015 we reported that the climate  information needs of federal, state, local, and private-sector decision  makers were not being fully met and that a national climate information  system could help them make more informed decisions about managing  climate change risks. We made two recommendations, including that the  Executive Office of the President develop a set of authoritative climate  change projections for use in federal decision making, but as of May  2018, the Executive Office of the President had yet to take action in  response. In 2016 we reported that improved federal coordination could  facilitate the use of forward-looking climate information in facilities design  standards and building codes, the technical guidelines that promote the  safety, reliability, productivity, and efficiency of infrastructure. We made  one recommendation—that the Director of the National Institute of  Standards and Technology at the Department of Commerce convene an  ongoing government-wide effort to provide the best available forward- looking climate information to standards-developing organizations for  consideration in design standards and building codes. As of May 2018,  our recommendation had not been implemented.

We have also previously reported on the risks of extreme weather and  climate change effects to DOD installations. In 2014, we reported on the  risks that climate change posed to DOD’s domestic installations, and in  2017 we issued a related report on risks that climate change posed to  DOD’s foreign installations. We discuss our findings and  recommendations from these reports in more depth later in this report.

Senate Report 115-130, accompanying a bill for fiscal year 2018  appropriations for military construction, the Department of Veterans  Affairs, and related agencies, cited concerns with the frequency and costs  of extreme weather events and the potential effects of climate change  and included a provision for us to review DOD’s progress in developing a  means to account for potentially damaging weather in its facilities project  designs. This report examines the extent to which DOD has taken steps  to incorporate resilience to extreme weather and climate change effects  into (1) installation master plans and related planning documents, and (2)  individual installation facilities projects.

For objective one, we reviewed DOD policies, guidance, and standards  related to increasing climate resilience and conducting installation master  planning. We interviewed officials in the Office of the Assistant Secretary  of Defense for Sustainment, each of the military departments involved  with installation policy, and the engineering organizations of each military  department. We also visited or requested information from a non- generalizable sample of 23 domestic military installations, plus an Air  Force unit with responsibility for certain facilities in Alaska because these  facilities are affected by severe coastal erosion. To develop this sample  we focused on domestic installations because our November 2017 report  focused on foreign installations. We selected installations that had  identified one or more climate-related vulnerabilities based on their past  experiences in a DOD-administered survey of climate vulnerabilities at  DOD installations or in a prior GAO report on weather and climate risks at  DOD installations. We visited 10 of these installations, plus the Air Force  unit in Alaska, and sent the remaining 13 installations a questionnaire.

We then reviewed documents from all the installations in our sample,  including master plans. We compared DOD’s actions to take steps in  installation planning to increase resilience with DOD guidance on climate  change resilience, Unified Facilities Criteria standards, federal internal  control standards, and best practices for enterprise risk management.

For objective two, we reviewed DOD guidance related to increasing  climate resilience. We also reviewed DOD standards for facilities project  design to determine the extent to which they require or give guidance on  climate resilience measures and the extent to which they incorporate  guidance on using climate projections. We obtained information from  each of the installations in our sample on the extent to which they had  incorporated climate resilience measures into specific projects and  reviewed project design documents. We compared the extent to which  DOD took steps in its facilities projects and its project design standards to  increase resilience with DOD guidance on climate change resilience. See  appendix I for more information on our objectives, scope, and  methodology.

We conducted this performance audit from April 2018 to June 2019 in  accordance with generally accepted government auditing standards.  Those standards require that we plan and perform the audit to obtain  sufficient, appropriate evidence to provide a reasonable basis for our  findings and conclusions based on our audit objectives. We believe that  the evidence obtained provides a reasonable basis for our findings and  conclusions based on our audit objectives.

Extreme Weather and Climate Change Effects

According to the National Research Council, although the exact details  cannot be predicted with certainty, climate change poses serious risks to  many of the physical and ecological systems on which society depends.  Moreover, according to key scientific assessments, the effects and costs  of extreme weather events such as floods and droughts will increase in  significance as what are considered rare events become more common  and intense because of climate change. According to the National  Academies of Sciences, Engineering, and Medicine, extreme weather  events are directly traceable to loss of life, rising food and energy prices,  increasing costs of disaster relief and insurance, fluctuations in property  values, and concerns about national security. Table 1 shows seven  effects commonly associated with climate change that DOD has  documented.

Sources of Climate Information and Projections

According to a 2010 National Research Council report on making  informed decisions about climate change and our October 2009 report  on climate change adaptation, most decision makers need a basic set of  information to understand and make choices about how to adapt to the  effects of climate change. This set of information includes information and  analysis about observed climate conditions, information about observed  climate effects and vulnerabilities, and projections of what climate change  might mean for the local area. In November 2015, we found that in order  for climate information to be useful, it must be tailored to meet the needs  of each decision maker, such as an engineer responsible for building a  bridge in a specific location, a county planner responsible for managing  development over a larger region, or a federal official managing a  national-scale program.

Agencies across the federal government collect and manage many types  of climate information, including observational records from satellites and  weather monitoring stations on temperature and precipitation, among  other things; projections from complex climate models; and tools to make  this information more meaningful to decision makers. For example, the  Fourth National Climate Assessment, completed in November 2018 by  the U.S. Global Change Research Program, references various sources  of climate information, including projected temperature and precipitation  data. Likewise, in 2016, a multi-agency group led by the Strategic  Environmental Research and Development Program (SERDP) developed  a report and accompanying database of future sea level projections and  extreme water levels, which as of May 2019 contained sea level change  projections for 1,813 DOD sites worldwide.

Climate projections are typically a range of possible future scenarios for  particular time frames. Multiple future scenarios allow for planners and  engineers to see a range of possible conditions that could occur at  various points in time. For example, a planner or engineer could consider  four different future scenarios occurring over the course of 20, 40, or 60  years or over the service life of the project being designed. Figure 1  shows an example of sea level change projections provided by the  National Oceanic and Atmospheric Administration (NOAA). Specifically,  the chart shows historical mean sea levels and multiple scenarios of  projected relative sea level rise in Norfolk, Virginia.

The chart shows the historical annual mean sea level from 1960 to 2018  through the bold black line. The projections use 2000 as a starting point,  and so overlap with the historical data. Relative sea level rise takes into  account changes in land levels—in the Norfolk area the land is generally  subsiding over time. Each scenario is based on different assumptions  about future greenhouse gas emissions, according to an official from  NOAA’s National Ocean Service. Planners and engineers can use the  multiple scenarios to evaluate when potential effects could occur and  determine their risk tolerances to inform their planning or design choices.  Figure 2 similarly shows the same historical mean sea levels at Norfolk,  Virginia, as well as the very likely range of projections of future relative  sea levels, according to the National Ocean Service.

This chart shows the range of possibilities considered very likely—those  between the low and intermediate scenarios in figure 1—according to an  official from NOAA’s National Ocean Service.

Installations’ Processes for Master Planning and Project Design

Master planning for military installations involves the evaluation of factors  affecting the present and future physical development and operation of a  military installation. DOD requires all installations to develop master  plans. DOD’s instruction on real property management states that plans  must be based on a strategic assessment of the operational mission and  expected use of the installation. The plans must cover at least a 10-year  period and be updated every 5 years, or more often if necessary. The  plans must include lists, by year, of all construction projects, major repair  and sustainment projects, and restoration and modernization projects  needed within the time period covered by the plan.

Design Standards for Individual Facilities Projects

Individual DOD facilities projects within installations must be designed in  accordance with DOD’s facilities design standards, which are defined in  the Unified Facilities Criteria. Unified Facilities Criteria are technical  manuals and specifications used for planning, design, construction,  maintenance, and operations of all DOD facilities projects. The U.S. Army  Corps of Engineers, Naval Facilities Engineering Command, and the Air  Force Civil Engineer Center are responsible for administering and  updating the Unified Facilities Criteria. The Unified Facilities Criteria  include a core group of 27 standards that apply to building systems found  in most DOD facility construction projects, and include standards such as  architecture, roofing, and civil engineering. Engineers and planners  apply the criteria that are most appropriate for their individual facilities  projects to their project proposals and designs. Table 2 shows excerpts  from requirements and guidance to project designers in the Unified  Facilities Criteria relevant to the consideration of climate.

Table 2. Excerpts from Unified Facilities Criteria Requirements and Guidance on Consideration of Climate  Excerpt   consider site-specific, long-term, climate change impacts such as  drought, flood, wind, and wildfire risks.

Knowing the probable wind speed and direction in a particular month can be helpful in construction  and mission planning as well as in designing structures that experience severe wind-driven rain or  drifting snow.

Pumps, piping, and equipment must be protected from the weather. In cold climates pumps and  piping must be protected from freezing temperatures. The pump station building must comply with   1-200-01 , be constructed of  noncombustible materials and meet applicable building standoff distances.

In new construction, the roof system selection is an integral part of the overall building design and  must take into account interior building usage and climate. For example, the building can be  designed to prevent outward moisture drive, support heavy roof systems (such as garden roofs or  paver systems), or sloped for the desired durability (life cycle cost benefit) and aesthetic  considerations.

Building shape, orientation, and design must utilize the site seasonal environmental factors to  minimize annual facility energy use and to optimize daylighting. Coordinate building and glazing  orientation and architectural shading with seasonal solar angles and prevailing winds to enhance  energy performance of the building within the site-specific micro climate.

Streets, paved parking lots, roofs, and other impermeable surfaces allow no infiltration of runoff  and provide little resistance to flow. Runoff draining from these surfaces can be highly  concentrated and move at a velocity greater than runoff flowing over an unpaved surface. Soils  must be protected from this erosive force, particularly at the edges of impermeable surfaces and  soils.   11988 directs all Federal agencies to avoid floodplain development wherever  there is a practicable alternative. When development within the floodplain is considered, evaluate  alternative site locations to avoid or minimize adverse impacts to the floodplain. When mission  needs require siting a building within or partially within the 100-year floodplain, indicate…the base  flood elevation…and the minimum design flood elevation….

DOD Infrastructure Costs Associated with Extreme Weather and Climate Change Effects

Extreme weather and climate change effects can damage infrastructure,  requiring repairs and resulting in budgetary risks (i.e., costs) to DOD.  While no individual weather event can be definitively linked to climate  change, particular weather events can demonstrate the vulnerability of  military facilities. For example, in October 2018, Hurricane Michael  devastated Tyndall Air Force Base in Florida, shutting down most base  operations until December; causing severe damage to the flight line,  drone runway, and other base facilities including family housing; and  destroying the base’s marina. The Air Force estimates that repairs at the  base will cost about $3 billion and take 5 or more years to complete.  Camp Lejeune and Marine Corps Air Stations Cherry Point and New  River in North Carolina sustained heavy damage to facilities, housing,  and training locations from Hurricane Florence in September 2018. The  Marine Corps estimates that the recovery from the hurricane damage will  cost about $3.6 billion and take years to complete.

In 2014, we reported that more frequent and more severe extreme  weather events and climate change effects may result in increased fiscal  exposure for DOD. In the same report, officials provided examples of  costs associated with extreme weather and climate change effects at  DOD facilities. For example, officials from a Navy shipyard we visited  stated that the catastrophic damage that could result from the flooding of  a submarine in dry dock could cause substantial repair costs. In 2017, we  found that DOD installations overseas face operational and budgetary  risks posed by weather events and climate change effects at the military  services’ installations in each of DOD’s geographic combatant  commands. We recommended that the Secretaries of the Army, Navy,  and Air Force work with the Office of the Secretary of Defense to issue a  requirement to their installations to systematically track the costs  associated with extreme weather events and climate change effects.  DOD did not concur with this recommendation. In its response, DOD  stated that tracking impacts and costs associated with extreme weather is  important, but that the science of attributing these events to a changing  climate is not supported by previous GAO reports. DOD also stated that  associating a single event with climate change is difficult and does not  warrant the time and money expended in doing so. However, as we  stated in our response to DOD’s comments, installations generally have  the capability to track the costs associated with extreme weather events,  which are projected to become more frequent and intense as a result of  climate change. 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. As of April 2019, the military departments have not implemented  this recommendation.

Some Installations Have Integrated Extreme Weather and Climate Considerations in Master Plans or Related Installation Planning Documents, but They Have Not Consistently Assessed Climate Risks or Used Climate Projections in These Plans

Some Installations Have Integrated Extreme Weather and Climate Considerations into Their Master Plans or Related Installation Planning Documents

Fifteen of the 23 installations we visited or contacted had integrated some  considerations of extreme weather or climate change effects into their  plans. For example,

Langley Air Force Base, Virginia, partnered with the City of Hampton,  Virginia, to study the effects of sea level rise. A 2018 addendum to the  installation’s 2010 joint land use study with the City of Hampton  outlined climate vulnerabilities and identified recommendations for  actions to increase installation resilience. Separately, after sustaining  damage from Hurricane Isabel in 2003, the installation required all  new development to be constructed to a minimum elevation of 10.5  feet above sea level, higher than the flooding associated with the  hurricane and one foot higher than the flooding anticipated from a  storm with a 1-in-500 chance of occurring in any given year. As DOD  noted in its January 2019 report to Congress on climate-related  vulnerabilities, Joint Base Langley-Eustis, of which Langley Air Force  Base is a part, has experienced 14 inches in relative sea level rise  since 1930, due in part to land subsidence, and has experienced  more frequent and severe flooding as a result.

The 611th Civil Engineer Squadron, based at Joint Base Elmendorf- Richardson in Alaska, partnered with the University of Alaska,  Anchorage, to develop site-specific predictive models of coastal  erosion for two radar sites on the North Slope of Alaska. The  squadron plans to use this information in the future to develop  possible alternative facilities projects to address the erosion risks.  Squadron officials told us they consulted with the military users of the  radars to determine the length of time to plan for their continued use  and that they intend to use this information to develop plans to  address this coastal erosion. The North Slope radar sites are  experiencing greater than anticipated coastal erosion rates, which  have begun to threaten the infrastructure supporting the sites.

Fort Irwin, California, in response to severe flash flooding in 2013 that  caused loss of power and significant damage to base infrastructure,  worked with the U.S. Army Corps of Engineers to develop a plan to  improve stormwater drainage. The 2014 plan recommended a series  of infrastructure projects, some of which Fort Irwin has implemented;  others remain to be implemented, depending on the availability of  funding. Figure 2 depicts flooding damage in 2013 at Fort Irwin and a  stormwater diversion channel subsequently built by the installation.  The flash flooding on the installation caused damage to roads and  other facilities throughout the installation, according to officials. The  installation subsequently raised berms and built other structures, such  as the diversion channel shown in figure 3, to divert stormwater from  installation facilities.

Marine Corps Recruit Depot Parris Island, South Carolina, reported  that the installation plans to award a contract to study sea level rise at  the installation and incorporate the results into the next iteration of its  master plan. The installation stated that incorporating the study’s  results is included in the scope of work for the contract that has been  awarded for the master plan update.

Naval Station Norfolk, Virginia, noted in its 2017 master plan that  climate change and sea level rise are expected to exacerbate effects  to the installation from tidal flooding and storm surge, increasing risks  to installation assets and capabilities. The plan established a goal of  identifying measures that could minimize the effect of sea level rise on  the installation. With the majority of the installation near mean sea  level, Naval Station Norfolk is vulnerable to frequent flooding that is  disruptive to operations. Figure 4 depicts flooding at Naval Station  Norfolk. Installation officials told us that such floods can interfere with  traffic on base, thus reducing the ability of those working on the  installation to transit within, to, and from the base.

Naval Base San Diego, California, noted in its most recent master  plan that local climate change effects include water and energy  shortages, loss of beaches and coastal property, and higher average  temperatures, among others. The plan also stated that Naval Base  San Diego should be funded to conduct a study to determine  installation-specific effects of sea level rise. Navy Region Southwest  subsequently partnered with the Port of San Diego to study local  effects of sea level rise, which installation officials said will help them  understand the effects of sea level rise on the base.

Camp Lejeune, North Carolina, participated in a study of the effects of  sea level rise on the installation and on certain other DOD installations  in North Carolina and Florida. An installation official stated that  installation officials have used the results of the study to make  planning decisions, in particular by feeding the study data into the  installation’s mapping of potential flood zones. The 10-year study,  which concluded in 2017, was funded by SERDP and was based at  Camp Lejeune to, among other things, understand the effects of  climate change at Camp Lejeune. Camp Lejeune officials and one of  the scientists involved in the study told us that installation officials  have used the study’s results to make decisions about where to site  buildings so as to take into account the possible future condition of  marshes on the base.

However, 8 of the 23 installations we visited or contacted had not  integrated considerations of extreme weather or climate change effects  into their master plans or related installation planning documents. For  example,  Joint Base Pearl Harbor Hickam, Hawaii, did not consider extreme  weather and climate change effects in its most recent master plan,  although it is located in an area that has been subject to tropical  storms and where, according to projections in the DOD database of  sea level change scenarios, further sea level rise is anticipated.  Specifically, under the highest scenario in the database, sea level at  Naval Station Pearl Harbor, part of the joint base, could rise more  than 3 feet by 2065. The lowest elevation point on the base is 0.6 feet  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.

Pearl Harbor Naval Shipyard, Hawaii, did not consider extreme  weather or climate change effects in its most recent master plan,  although it is co-located with Joint Base Pearl Harbor Hickam and  therefore shares the same weather and climate conditions noted  previously.

Fort Wainwright, Alaska, officials told us they had not considered  climate change as part of the installation’s master planning. Officials  noted that the majority of the base is on thaw-stable permafrost that  would be unlikely to be significantly affected by rising temperatures,  but some areas of the base are on less stable permafrost. DOD noted  in its January 2019 report to Congress that thawing permafrost can  decrease the structural stability of buildings and other infrastructure  that is built on it.

Camp Pendleton, California, officials told us that although they are  aware of a variety of climate-related challenges to their installation  and have taken or plan to take some steps to address them, an  example of which we discuss later in this report, the installation has  not yet considered extreme weather and climate change effects in its  master plan. The officials stated that they are still planning based on  historical conditions rather than considering possible future conditions.

DOD’s Unified Facilities Criteria standard specific to master planning  states that where changing external conditions affect planning decisions,  master planners should seek to understand, monitor, and adapt to these  changes, including changes in climatic conditions such as temperature,  rainfall patterns, storm frequency and intensity, and water levels. DOD’s  directive on climate change adaptation further states that military  departments should integrate climate change considerations into their  plans. The directive also states that the Assistant Secretary of Defense  for Energy, Installations, and Environment should consider climate  change adaptation and resilience in the installation planning process,  including the effects of climate change on both built and natural  infrastructure.

Our findings based on the 23 installations we reviewed for this report are  consistent with our prior reports on extreme weather and climate change  effects at military installations. Specifically, installations have not  consistently integrated these considerations into their master plans or  related installation planning documents. In May 2014, we reported that  some domestic installations had integrated considerations of changing  climatic conditions into their installation planning documents, but DOD  had not provided key information—such as how to use climate change  projections—to help ensure that efficient and consistent actions would be  taken across installations. We recommended that DOD further clarify the  planning actions that should be taken in installation master plans to  account for climate change, to include further information about changes  in applicable building codes and design standards that account for  potential climate change effects and further information about potential  projected climate change effects on individual installations. However, as  of January 2019, DOD had not fully implemented this recommendation.

For example, as we discuss later in this report, DOD’s updates to its  facilities design standards lacked guidance on the use of climate  projections. DOD also had not provided information on a range of  potential effects of climate change on individual installations. DOD has  taken some positive steps in this area, such as making available to the  military services a database of sea level change scenarios for 1,774 DOD  sites worldwide. However, DOD has not provided other specific types of  climate projections, which we discuss in more depth later in this report.

Moreover, in November 2017 we reported that about a third of the  installations in our sample of overseas installations had integrated climate  change adaptation into their installation plans, but the lack of key  guidance and updated design standards to reflect climate change  concerns hampered their ability to consistently incorporate climate  change adaptation into their plans. We recommended, among other  things, that the military departments integrate climate change data and  projections into DOD’s facilities criteria and periodically revise those  standards based on any new projections, as appropriate. DOD partially  concurred, and as of January 2019, an official from the Office of the  Assistant Secretary of Defense for Sustainment stated that the office was  continuing to work with the military departments to evaluate how to  effectively translate the latest climate data into a form usable by  installation planners and facilities project designers. Based on our  findings for this review, we continue to believe that DOD should take all  necessary steps to implement these recommendations.

Installations Have Not Fully Assessed Risks from Extreme Weather and Climate Change Effects in their Master Plans and Related Installation Planning Documents

While 15 of the 23 installations we visited or contacted had integrated  some consideration of extreme weather or climate change effects into  their planning documents, only two of these installations had taken steps  to fully assess the weather and climate risks to the installation or develop  plans to address identified risks. DOD has taken some broad actions to  assess risk to installations from extreme weather and climate change  effects. For example, in January 2018, DOD issued a report to Congress  on the results of its survey of installations on the extent to which they  faced a variety of extreme weather or climate effects. However, the  survey responses constituted a preliminary assessment and were based  on installations’ reporting of negative effects they had already  experienced from extreme weather effects, rather than assessments of all  future vulnerabilities based on climate projections. DOD noted that the  information in the survey responses is highly qualitative and is best used  as an initial indicator of where a more in-depth assessment may be  warranted.

However, except for two of the installations in our sample, the  installations’ master plans and related installation planning documents did  not (1) identify a range of possible extreme weather events and climate  change effects that could affect the installation, (2) assess the likelihood  of each event occurring and the possible effect on the installation, and (3)  identify potential responses to these events. For example, Naval Air  Station Key West, Florida, included discussion of the effects of sea level  rise and storm surge on the installation in its master plan, as well as steps  it could take to mitigate these effects. However, although the installation  experienced drought conditions rated severe in 2011 and extreme in  2015, its master plan does not discuss effects on the installation of  drought, which, according to a DOD report to Congress, can pose  significant risks to an installation, including implications for base  infrastructure. All of the Air Force installations in our sample rated their  degree of vulnerability to a range of climatic conditions—such as flood,  temperature rise, and precipitation pattern changes—in their master  plans, thereby identifying a range of possible climate events and the likelihood of each event. However, of those installations that identified a  range of possible extreme weather and climate change effects that could  affect the installation, most did not consistently identify potential  responses to these events. The two exceptions—Eglin Air Force Base,  Florida, and Joint Base Langley-Eustis, Virginia—took the additional step  of identifying possible actions to address these climate events. For  example, Eglin Air Force Base rated itself as having a high vulnerability to  storm surge, but a low vulnerability from rising temperatures, and  identified steps the installation could take in facilities planning and design  to mitigate the identified risks.

The DOD directive on climate adaptation states that military departments  should assess and manage risks to both built and natural infrastructure,  including changes as appropriate to installation master planning, and  should assess, incorporate, and manage the risks and effects of altered  operating environments on capabilities and capacity, including basing.  Moreover, Standards for Internal Control in the Federal Government  states that management should identify, analyze, and respond to risks  related to achieving defined objectives. Risk assessment is the  identification and analysis of risks related to achieving defined objectives  in order to form a basis for designing responses to these risks. Our prior  work has shown that assessing risks includes assessing both the  likelihood of an event occurring and the effect the event would have.  Agency leaders and subject matter experts should assess each risk by  assigning the likelihood of the event’s occurrence and the potential effect  if the event occurs.

Despite a DOD directive requiring that the military departments assess  and manage risks to both built and natural infrastructure, DOD has not  required in the Unified Facilities Criteria standard that guides master  planning that installations assess risks posed by extreme weather and  climate change effects as part of their master plans or develop plans to  address identified risks. Officials in the Office of the Assistant Secretary of  Defense for Sustainment acknowledged that the Unified Facilities Criteria  standard on master planning does not explicitly require a risk assessment  specifically for extreme weather or climate change as part of the master  planning process. Because installations have not consistently assessed  the risks from extreme weather and climate change effects as part of their  master plans or identified potential responses to identified risks, they may  formulate plans and make planning decisions without consideration of  those risks. By assessing and developing actions to address these risks  in their master plans, installations could better anticipate exposure of the  facilities to greater than anticipated damage or degradation as a result of  extreme weather events or climate change effects.

Installations Have Not Consistently Used Climate Projections in Developing Master Plans

Eight of the 23 installations we visited or contacted, as well as the Air  Force unit responsible for the North Slope radar facilities, had made some  use of climate projections to incorporate consideration of extreme  weather and climate change effects into their master plans or related  installation planning documents. For example, as noted previously, the  611th Civil Engineer Squadron was developing its own site-specific  projections of coastal erosion affecting the North Slope radar sites in  Alaska, and Norfolk Naval Shipyard considered local sea level rise  projections in a study on mitigating flooding at its docks. However,  officials from 11 of the 23 installations in our sample—including some  from installations that had made some use of climate projections—cited  the need for additional guidance from DOD or their military department  headquarters on which projections to use in planning or on how to use  them.

This is consistent with our prior findings on DOD’s installation-level efforts  to increase climate resilience. Our May 2014 report noted that installation  officials told us they did not have the installation-level climate data from  their military departments or from other DOD sources that they would  need to understand the potential effects of climate change on their  installations. We recommended, among other things, that DOD provide  further direction on planning actions to account for climate change,  including information about changes in applicable building codes and  design standards and the projected effects of climate change on individual installations. DOD concurred but as of January 2019 had not  fully implemented this recommendation, as noted previously. In  December 2018, an official in the Office of the Assistant Secretary of  Defense for Sustainment stated that DOD plans to develop a policy on  the use of sea level rise projections by some time in 2019 and eventually  to incorporate these projections into the Unified Facilities Criteria.  However, DOD has no current time table for incorporating guidance on  the use of other types of climate projections into its Unified Facilities  Criteria. The official stated that the department is working toward  eventually incorporating the use of other types of climate projections into  guidance but that these types of projections would have to be vetted by  DOD subject matter experts and approved prior to adoption. DOD intends  to move in this direction, according to the official, but DOD has not yet  developed a defined process for evaluating and incorporating the use of  additional climate projections into guidance.

Our prior work has found that using the best available climate information,  including forward-looking projections, can help an organization to manage  climate-related risks. Until November 2018, DOD’s Unified Facilities  Criteria on master planning stated that changes in climate conditions are  to be determined from reliable and authorized sources of existing data but  that to anticipate conditions during the design life of existing or planned  new facilities and infrastructure, installations could also consider climate  projections from reliable and authorized sources, such as, among others,  the U.S. Global Change Research Office and the National Climate  Assessment. In November 2018, in response to a statutory requirement in  the John S. McCain National Defense Authorization Act for Fiscal Year  2019, DOD updated the Unified Facilities Criteria on master planning to  specify that climate projections from reliable and authorized sources,  such the U.S. Global Change Research Office and the National Climate  Assessment, shall be considered and incorporated into military  construction designs and modifications. DOD guidance states that the  Assistant Secretary of Defense for Energy, Installations, and Environment  provides guidance and direction on relevant technologies, engineering  standards, tools, development and use of scenarios, and other  approaches to enable prudent climate change adaptation and resilience.  The guidance also states that military departments are to leverage  authoritative environmental prediction sources for appropriate data and  analysis products to assess the effects of weather and climate.

Installations have not consistently used climate projections in their master  plans because DOD has not provided detailed guidance on how to do so.  Simply updating the language of the Unified Facilities Criteria on master  planning in November 2018 to require the use of climate projections does  not provide guidance to installations on how to use climate projections,  such as what future time periods to consider and how to incorporate  projections involving multiple future scenarios, nor does it identify the  specific types of projections to use. The absence of guidance has  hindered the ability of some installations to effectively apply the best  available climate projections to their installation master planning. If they  do not use climate projections in their master plans, installations risk  failing to plan for changing climate and weather conditions and, as a  result, could expose their facilities to greater risk of damage or  degradation from extreme weather events and climate change effects.  Incorporating such data into planning would help installation master  planners better anticipate changing climate and weather conditions and  increase the effectiveness of the installation’s long-term investments in its  facilities.

Installations Have Designed Some Individual Facilities Projects to Increase Resilience to Extreme Weather, but They Lack Guidance on Using Climate Projections

Some Installations Have Designed Individual Facilities Projects with Elements of Resilience to Extreme Weather or Climate Change Effects

Eleven of the 23 installations we visited or contacted had designed or  constructed one or more individual facilities projects to increase the  resilience of the facilities themselves, or to increase the resilience of the  installation more broadly, to extreme weather and climate change effects.  For example,  Joint Base Langley-Eustis, Virginia. In 2018, officials designed a  project to build a maintenance hangar with a special foundation that  would elevate the floor to 10 feet above the average high-water level  at the project site and protect it against coastal storm flooding. Joint  Base Langley-Eustis has experienced severe flooding in the past  because of its low-lying geographical elevations in the Chesapeake  Bay. The installation stated in its draft encroachment management  action plan that the effects of climate change may exacerbate flooding  issues through sea level rise or the increasing frequency and severity  of storms.

Norfolk Naval Shipyard, Virginia. In 2018, shipyard officials designed  a project to increase the installation’s resilience to storm-induced  flooding, including building a floodwall to protect the dry docks that are  used to perform maintenance on ships and submarines. Norfolk Naval  Shipyard experiences extreme high tides three to five times a year on  average and a significant hurricane on average once a year,  according to an installation presentation, and flooding has been  increasing over time in the area as relative sea levels have risen. The  floodwall will enclose the dry docks, providing protection to critical  assets and electrical utilities while they are in dry dock, among other  things. Figure 5 depicts a flooded dry dock at Norfolk Naval Shipyard,  Virginia. Installation officials told us that flooding into dry docks poses  risks to the ships being serviced there and to the performance of the  base’s mission of servicing and maintaining Navy ships and  submarines.

Camp Pendleton, California. In 2018, as part of a project to construct  a new aircraft landing zone, officials included protection of the nearby  coastline, which had been rapidly eroding from the impact of ocean  waves and rain storms. According to officials, the erosion has  accelerated in recent years and has threatened not only landing  zones along the coast, but also beaches that are used for amphibious  assault training. Figure 6 depicts coastal erosion near a landing zone  at Camp Pendleton, California. According to officials, the erosion  leading to the gulley shown in the photograph has accelerated in  recent years and advances further inland every year; it is now within  feet of the landing zone. The officials told us that the erosion can  threaten the function of the landing zone if it reaches that site.

Fort Shafter, Hawaii. In 2016, officials constructed flood mitigation  structures, including a flood control levee, to protect maintenance  facilities being built in a flood zone. At the time, there were no  adequate permanent maintenance facilities for units stationed at the  base, and the only available land big enough to support the proposed  maintenance facilities was located within a flood zone.

Most Installations Have Not Used Climate Projections in Designing Individual Facilities Projects

Despite limited efforts to increase the resilience of facilities to extreme  weather and climate change effects, officials from 17 of the military  installations in our sample said that their individual facilities project  designs generally did not consider climate projections. Of the installations  that stated that they considered climate projections in facilities project  designs, one military installation said it uses a study on sea level rise at  the installation as a tool that incorporates forward-looking projections, and  another installation said it uses a NOAA web-based tool, Sea Level Rise  Viewer, for graphical representations of projected sea level rise. One  installation noted that it had considered sea level rise projections in a pier  design, which we discuss further below. A fourth installation said it plans  to use a draft Navy study on the vulnerability of coastal Navy installations  to sea level rise to inform an upcoming facilities project design. However,  another installation said it has used energy consumption projections,  which are not climate projections, and another installation cited a Navy  climate adaptation handbook, which does not include climate projections  for individual Navy installations.

Moreover, over the course of our review of 23 installations, we were able  to identify only one project as having a design informed by climate  projections. Specifically, in 2018, officials from Naval Base San Diego,  California, designed a project to demolish and replace an existing pier.  The project’s design was informed by the expectation of sea level rise  over the 75-year lifespan of the pier. An installation official told us that the  consideration of rising sea levels was not part of the original project  proposal, but when a contractor provided the sea level rise projections,  installation officials decided to raise the pier by one foot. Figure 7 depicts  a notional example of a pier—not specific to San Diego or any other  particular location—raised to account for sea level rise. The Unified  Facilities Criteria on piers and wharves states that the bottom elevation of  the deck slab should be kept at least one foot above the extreme high  water level. In this notional example, the pier is raised to account for an  anticipated one-foot sea level rise, so that the bottom of the deck slab  remains one foot above the extreme high water level, as shown in the  figure.

DOD guidance requires the military departments to assess and manage  risks to both built and natural infrastructure, including making changes, as  appropriate, to design and construction standards. The guidance also  requires the military departments to leverage authoritative environmental  prediction sources for appropriate data and analysis products to assess  weather and climate effects.

However, DOD’s Unified Facilities Criteria pertaining to project design,  with the exception of the standard on high performance and sustainable  building requirements, do not require consideration of climate projections  as part of facilities project designs. The Unified Facilities Criteria standard  on high performance and sustainable building requirements requires  engineers to provide building design solutions that are responsive to any  government-provided projections of climate change and determination of  acceptable risk. We analyzed 27 core Unified Facilities Criteria, as well  as 3 other Unified Facilities Criteria, Installation Master Planning, Design:  Engineering Weather Data, DOD Building Code (General Building  Requirements), and one facility criteria standard on Navy and Marine  Corps Design Procedures. Our analysis showed that as of March 2019  these criteria, other than the Unified Facilities Criteria standard on  installation master planning, do not identify authoritative sources of  climate projections for use in facilities project designs. The Unified  Facilities Criteria standard on installation master planning states that  climate projections from the U.S. Global Change Research Program and  the National Climate Assessment as well as the National Academy of  Sciences shall be considered and incorporated into military construction  designs and modifications. However, an official in the Office of the  Assistant Secretary of Defense for Sustainment acknowledged that this  requirement in the standard on installation master planning is not  sufficient on its own to apply to all facility project designs. Additionally, the  standard on installation master planning does not identify the specific  types of climate projections to use or how to locate them. Our analysis  showed that the Unified Facilities Criteria do not provide guidance on how  to incorporate projections into facilities project designs, such as how to  use projections involving multiple future scenarios and what future time  periods to consider.

We found that while some Unified Facilities Criteria direct project  designers to climate data, these are historical climate data rather than  projections. For example, the following standards do not direct project  designers to sources of climate projections:  2015) (change 1, Feb. 1, 2016). This guidance directs project  designers to use long-term rainfall records, such as those from  regional weather stations, and directs engineers toward a table that  provides rainfall data for selected locations. However, information  included in the guidance is historical and does not include or refer to  projections.

Unified Facilities Criteria 3-400-02, Design: Engineering Weather Data  (Sept. 20, 2018). This guidance directs project designers toward  instructions for accessing climate data for use in designing facilities  and in mission planning. However, the guidance does not discuss the  use of or specifically reference climate projections.

Unified Facilities Criteria 3-201-01, Civil Engineering (Apr. 1, 2018)  (change 1, Mar. 19, 2019). This guidance requires project designers  to plan for flood hazard areas and, if the project is constructed within  the 100-year floodplain, requires that the project design document  include flood mitigation measures as part of the project’s scope of  work. However, the guidance does not include or reference  projections that would help engineers design for various potential  flooding scenarios.

As previously noted, in response to a statutory requirement, DOD  updated its Unified Facilities Criteria on master planning in November  2018 to require installations to consider and incorporate reliable and  authorized sources of data on changing environmental conditions.  However, simply including this language does not provide guidance to  installations on what sources of climate projections to consider and how  to use them in designing facilities projects, such as what future time  periods to consider and how to incorporate projections involving multiple  future scenarios. In addition, the Unified Facilities Criteria standard on  master planning provides requirements and guidance for installation  master planning but not for the design of individual facilities projects. An  official of the Office of the Assistant Secretary of Defense for Sustainment  stated that his office plans to develop a policy on the use of sea level rise  projections by some time in 2019 and eventually to incorporate guidance  on how to use sea level rise projections into the Unified Facilities Criteria  or other guidance. This official added that there is currently no defined  DOD process for vetting authoritative sources of climate projections, but  that DOD plans to continue vetting sources for possible use, as  appropriate.

Furthermore, officials of 10 of the 23 military installations we reviewed  stated that in order to incorporate such projections into project designs,  they would need additional guidance from DOD or their military  departments identifying authoritative sources of such projections or how  to use climate projections that involve multiple future scenarios and  different time periods. Ultimately, installations that do not consider climate  projections in the design of their facilities projects may be investing in  facilities projects without considering potential risks, such as potential  future damage and degradation, which are associated with additional  costs and reductions in capability. If DOD does not provide guidance on  the use of climate projections in facilities designs, including what sources  of climate projections to use, how to use projections involving multiple  future scenarios, and what future time periods to consider, installation  project designers will continue to lack direction on how to use climate  projections. Further, if DOD does not update the Unified Facilities Criteria  to require installations to consider climate projections in project designs  and incorporate the department’s guidance on how to use climate  projections in project designs, installation project designers may continue  to exclude consideration of climate projections from facilities project  designs. Considering climate projections in facilities projects would help  DOD to reduce the climate-related risks to its facilities investments.

DOD has a global real estate portfolio that supports the department’s  global workforce and its readiness to execute its national security  missions. The department has repeatedly acknowledged the threats of  extreme weather and climate change effects to its installations, and as we  have previously reported, has begun taking steps to increase the  resilience of its infrastructure to these threats. We found that 15 of the 23  the installations we visited or contacted had considered some type of  extreme weather or climate change effects in their plans, a positive step  toward increasing resilience to these climate risks. However, not all had  done so and most of the installations we visited or contacted did not fully  assess the risks associated with extreme weather and climate change  effects—including the likelihood of the threat, potential effects on the  installation, and possible responses to mitigate such effects. Likewise,  many of the installations did not consider climate projections in planning.  Without fully assessing the risks of extreme weather and climate change  effects, and without considering climate projections as part of the  planning process, installations may make planning decisions that do not  fully anticipate future climate conditions. By seeking to anticipate future  climate conditions, DOD may be able to reduce climate-related risks to its  facilities and the corresponding budgetary risks.

Eleven of the 23 installations we visited or contacted had designed or  implemented one or more construction projects that incorporated  resilience to extreme weather or climate change effects. These projects  illustrate some of the steps that can be taken to increase an installation’s  resilience to climate risks. However, most of the installations had not  considered climate projections in project design. Considering climate  projections in facilities projects would help DOD to reduce the climate- related risks to its facilities investments. By updating its facilities project  design standards to require installations to consider climate projections in  project designs, identifying authoritative sources of climate projections,  and providing guidance on how to use climate projections, DOD can aid  installations to better position themselves to be resilient to the risks of  extreme weather and climate change effects.

We are making eight recommendations, including two to DOD and two to  each of the military departments. Specifically,  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)

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)

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)

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)

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)

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)

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)

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)

We provided a draft of this report for review and comment to DOD and  NOAA. In written comments, DOD concurred with all eight of our  recommendations and identified actions it plans to take to address two of  them. DOD’s comments are reprinted in their entirety in appendix II. DOD  also provided technical comments, which we incorporated as appropriate.  NOAA did not provide any comments on the draft.

We are sending copies of this report to the appropriate congressional  addressees; the Secretary of Defense; the Secretaries of the  Departments of the Army, Navy, and Air Force; and the Secretary of  Commerce (for NOAA). In addition, this report will be available at no  charge on the GAO website at http://www.gao.gov.

If you or your staff have any questions about this report, please contact  Diana Maurer at (202) 512-9627 or at maurerd@gao.gov. Contact points  for our Offices of Congressional Relations and Public Affairs may be  found on the last page of this report. GAO staff who made key  contributions to this report are listed in appendix III.

Senate Report 115-130, accompanying a bill for fiscal year 2018  appropriations for military construction, the Department of Veterans  Affairs, and related agencies, cited concerns with the frequency and costs  of extreme weather events and the potential effects of climate change,  and included a provision for us to review the Department of Defense’s  (DOD) progress in developing a means to account for potentially  damaging weather in its project designs. In response to this provision,  we examined the extent to which DOD has taken steps to incorporate  resilience to extreme weather and climate change effects into (1)  installation master plans and related planning documents, and (2)  individual installation facilities projects.

For both of our objectives, we visited or requested information from a  sample of domestic military installations. We focused on domestic  installations because our November 2017 report focused on foreign  installations. To develop this sample, we selected installations in the  continental United States, Alaska, Hawaii, and U.S. territories that had  identified one or more climate-related vulnerabilities, based on their past  experiences, in a DOD-administered survey of climate vulnerabilities, or  installations that were referenced in a prior GAO report on weather and  climate risks at DOD installations. In addition to these criteria, we  selected sites that represented both a diversity in types of climate  vulnerabilities and geographic diversity among the military services, as  well as installations involved in any climate change-related pilot studies.  From these criteria, we developed a non-generalizable sample of 23  installations. We also included in the sample one Air Force unit (not an  installation) with responsibilities for particular facilities of interest in  Alaska, because these facilities presented a climatic vulnerability  (accelerating coastal erosion) that was not necessarily included  elsewhere in the sample.

We visited 10 of these installations, as well as the Air Force unit in  Alaska, in person. Within the sample, we selected installations to visit  based on geographic diversity and installations in proximity to each other,  allowing us to visit multiple installations on each trip. For the remaining 13  installations, we developed and administered a questionnaire and  document request. We received responses from 12 of these installations.  One installation—Camp Lejeune—sustained significant damage from  Hurricane Florence in September 2018, and to minimize the burden on  installation officials’ time to respond, we met with them by phone. Results  from our nongeneralizable sample cannot be used to make inferences  about all DOD locations. However, the information from these installations  provides valuable insights. We asked similar questions to installations on  our site visits and in the questionnaires, and we collected similar  documents—such as installation master plans and individual facilities  project documents— allowing us to report on similar information, such as  the extent to which extreme weather and climate change considerations  were integrated into installation master plans and individual facilities  projects.

For objective one, we reviewed DOD policies, guidance, and standards  related to increasing climate resilience and conducting installation master  planning. These documents included, among others, DOD Directive  4715.21, which establishes policy and assigns responsibilities for DOD to  assess and manage risks associated with climate change; DOD’s Unified  Facilities Criteria standard on installation master planning, which  establishes the requirements for installation master plans; and a  memorandum from the Office of the Under Secretary of Defense for  Acquisition, Technology and Logistics on floodplain management on DOD  installations. We interviewed officials in the Office of the Assistant  Secretary of Defense for Sustainment and the Strategic Environmental  Research and Development Program. We also interviewed officials in  each of the military departments, including officials involved with  installation policy, as well as officials from the engineering organizations  of each military department and officials in the National Oceanic and  Atmospheric Administration to discuss climate science and the data  potentially available for planners to use. We reviewed documents from  each of the 23 installations and the one Air Force unit in our sample,  including master plans, and used interviews with installation officials and  questionnaires received from installations to determine the extent to  which the installations had incorporated consideration of extreme weather  and climate change effects into their installation plans. We compared  DOD’s actions to take steps in installation planning to increase resilience  to extreme weather and climate change effects with DOD guidance on  climate change adaptation and resilience, Unified Facilities Criteria  standards, federal internal control standards, and best practices for  enterprise risk management.

For objective two, we reviewed DOD guidance, including DOD Directive  4715.21, requiring DOD components to integrate climate change  considerations into DOD plans. We also reviewed DOD’s facilities project  design standards—the Unified Facilities Criteria—to determine the extent  to which installations incorporated requirements for climate resilience and  to identify any required or recommended climate data sources for facilities  project design. Specifically, we reviewed the 27 core Unified Facilities  Criteria standards, as well as 3 other Unified Facilities Criteria standards  outside of the core 27—because of their broad relevance to project  design—and one facility criteria on Navy and Marine Corps design  procedures. Additionally, we performed a content analysis of these  criteria for references to climate, weather, environment, and any climate  data to be used as a basis for facilities design. We also identified any  required or recommended climate data sources or tools for facilities  design by searching for references, web links, or tables related to climate  data within the criteria. Where climate data sources were identified, we  reviewed them to determine the extent to which the sources and tools  involved historical data or climate projections that anticipate future climate  conditions. We interviewed officials from the U.S. Army Corps of  Engineers, Naval Facilities Engineering Command, and the Air Force Civil  Engineer Center to understand the extent to which the Unified Facilities  Criteria include guidance or data sources for adapting DOD facilities to  extreme weather and climate change effects.

In addition, we used interviews with installation officials and  questionnaires we received from installations to determine the extent to  which the installations had planned or executed any military construction  or sustainment, restoration, and modernization facilities projects since  2013 that included any elements for building resilience to extreme  weather or climate change effects. We then reviewed project  documentation for proposed or approved facilities projects to identify the  resilience measures taken. We also observed some facilities-related  climate resilience measures adopted by these installations. In addition,  we interviewed officials from the Office of the Assistant Secretary of  Defense for Sustainment to determine what plans, if any, the office had to  update Unified Facilities Criteria with climate resilience requirements. We  also interviewed officials from the Office of the Assistant Secretary of the  Army for Installations, Energy and Environment; the Office of the  Assistant Secretary of the Navy for Energy, Installations and  Environment; and the Office of the Assistant Secretary of the Air Force,  Installations, Environment and Energy to identify any actions, policies, or  processes related to adapting facilities to extreme weather and climate  change effects. Moreover, we interviewed officials from the American  Society of Civil Engineers to understand what efforts, if any, had been  made to incorporate climate projections into industry standards. Finally,  we compared the extent to which DOD took steps in its facilities projects  and its project design standards to increase resilience with DOD guidance  on climate change resilience.

Table 3 lists the locations we visited or contacted during this review,  including the installations receiving our questionnaire.

Appendix II: Comments from the Department of Defense

Appendix III: GAO Contact and Staff Acknowledgments

Diana Maurer at (202) 512-9627 or maurerd@gao.gov.

In addition to the contact named above, Brian J. Lepore (Director, retired),  Kristy Williams (Assistant Director), Michael Armes, Kendall Childers,  Simon Hirschfeld, Joanne Landesman, Amie Lesser, Grace Meany,  Shahrzad Nikoo, Samantha Piercy, Monica Savoy, Benjamin Sclafani,  Joseph Dean Thompson, and Jack Wang made key contributions to this  report.

High-Risk Series: Substantial Efforts Needed to Achieve Greater  Progress on High-Risk Areas, GAO-19-157SP. Washington, D.C.: March  6, 2019.

Climate Change: Analysis of Reported Federal Funding. GAO-18-223.  Washington, D.C.: April 30, 2018.

Climate Change Adaptation: DOD Needs to Better Incorporate Adaptation  into Planning and Collaboration at Overseas Installations. GAO-18-206.  Washington, D.C.: November 13, 2017.

Climate Change: Information on Potential Economic Effects Could Help  Guide Federal Efforts to Reduce Fiscal Exposure. GAO-17-720.  Washington, D.C.: September 28, 2017.

High-Risk Series: Progress on Many High-Risk Areas, While Substantial  Efforts Needed on Others. GAO-17-317. Washington, D.C.: February 15,  2017.

Climate Change: Improved Federal Coordination Could Facilitate Use of  Forward-Looking Climate Information in Design Standards, Building  Codes, and Certifications. GAO-17-3. Washington, D.C.: November 30,  2016.

Defense Infrastructure: DOD Efforts to Prevent and Mitigate  Encroachment at Its Installations. GAO-17-86. Washington, D.C.:  November 14, 2016.

Climate Information: A National System Could Help Federal, State, Local,  and Private Sector Decision Makers Use Climate Information.  GAO-16-37. Washington, D.C.: November 23, 2015.

High-Risk Series: An Update. GAO-15-290. Washington, D.C.: February  11, 2015.

Budget Issues: Opportunities to Reduce Federal Fiscal Exposures  Through Greater Resilience to Climate Change and Extreme Weather.  GAO-14-504T. Washington, D.C.: July 29, 2014.

Climate Change Adaptation: DOD Can Improve Infrastructure Planning  and Processes to Better Account for Potential Impacts. GAO-14-446.  Washington, D.C.: May 30, 2014.

Extreme Weather Events: Limiting Federal Fiscal Exposure and  Increasing the Nation’s Resilience. GAO-14-364T. Washington, D.C.:  February 12, 2014.

Climate Change: Energy Infrastructure Risks and Adaptation Efforts.  GAO-14-74. Washington, D.C.: January 31, 2014.

Climate Change: Federal Efforts Under Way to Assess Water  Infrastructure Vulnerabilities and Address Adaptation Challenges.  GAO-14-23. Washington, D.C.: November 14, 2013.

Climate Change: State Should Further Improve Its Reporting on Financial  Support to Developing Countries to Meet Future Requirements and  Guidelines. GAO-13-829. Washington, D.C.: September 19, 2013.

Climate Change: Various Adaptation Efforts Are Under Way at Key  Natural Resource Management Agencies. GAO-13-253. Washington,  D.C.: May 31, 2013.

Climate Change: Future Federal Adaptation Efforts Could Better Support  Local Infrastructure Decision Makers. GAO-13-242. Washington, D.C.:  April 12, 2013.

High-Risk Series: An Update. GAO-13-283. Washington, D.C.: February  14, 2013.

International Climate Change Assessments: Federal Agencies Should  Improve Reporting and Oversight of U.S. Funding. GAO-12-43.  Washington, D.C.: November 17, 2011.

Climate Change Adaptation: Federal Efforts to Provide Information Could  Help Government Decision Making. GAO-12-238T. Washington, D.C.:  November 16, 2011.

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.