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Climate-forward defence

Adding a climate lens to decision-making can help militaries better understand the operational environment and uncover opportunities to enhance mission success.


The armed forces’ job is to protect national security, not tackle climate change. But climate change can be both a risk and an opportunity to achieve mission goals.

Temperature extremes, drought, sea-level rise and extreme weather events inflict costly harm on armed forces installations and degrade key armed forces capabilities. Climate change is also a threat multiplier that aggravates poverty, political instability and social tensions around the globe.

The US Department of Defense (DoD) is prioritising action on climate change to support its missions. In 2021, Secretary of Defense Lloyd J. Austin declared global climate change an existential threat to US national security, using language normally applied to threats such as nuclear attacks.1 DoD has developed an aggressive Climate Adaptation Plan that calls for “future-proofing” armed forces installations, building a climate-ready force, securing supply chains against extreme weather events and pursuing climate-informed decision-making.2

These measures are important but largely reactive. DoD’s current climate strategy primarily focusses on resilience; on protecting installations and operations from extreme weather events. But climate change may also create new opportunities and entirely new missions. For example, rising sea levels can affect potential amphibious landing zones in Pacific islands; overfishing in contested waters may create new opportunities for information operations (IO); and food shortages in nations dependent on imports may require armed forces intervention. While resilience is crucial to mission success, DoD’s climate approach should also include the identification of new armed forces advantages.

By seeing climate change as an inextricable part of the operational environment, armed forces leaders can consider how to use it to further their missions. Our adversaries have already begun thinking about climate in this way; If we don’t, we may miss a vital opportunity.

The shift from a reactive to a proactive approach to climate doesn’t require billions in new investments. With relatively minor changes to internal processes, DoD can create an armed forces that is both more resilient and more effective in the face of climate change.

Climate as an integral part of the operational environment

Just as weather is an essential part of tactical operations, climate is integral to the strategic operating environment. By expanding the scope of defence analysis to see climate as a central part of any operational environment, in much the same way armed forces leaders consider political, military, informational and other factors, DoD can discover new means of achieving its missions (figure 1).

Climate change is beginning to open up entirely new missions. Melting ice caps, for example, are making the Arctic more accessible each year. Retreating ice has increased human activity in the region, making transport, tourism and the exploitation of natural resources feasible for the first time.3 To gain control of these natural resources and new trade routes, several nations are steadily increasing their armed forces presence in the Arctic.4 DoD has begun enhancing its ability to operate in harsh Arctic conditions; for example, it’s working with the Department of Homeland Security to expand the US Coast Guard’s icebreaker fleet.5

But the Arctic isn’t the only area in which climate change is enabling new missions. In some cases, these will be familiar missions in new geographies, such as naval operations along altered coastlines. In other cases, entirely new missions may emerge—new targets for IO, new armed forces support for diplomatic or economic efforts and even new avenues for warfare.

The US military doctrine emphasises a thorough understanding of the strategic and operational environment.6 Climate change calls for an entirely new approach to the operational environment, one that considers how it will affect each mission. By doing so, planners can obtain a broader, more accurate understanding that can reveal additional factors affecting adversary or neutral behaviour, shift perceptions of adversary centre of gravity and determine new ways to achieve objectives. Adding a climate lens to operational environment assessments can help increase mission effectiveness, a missing dimension that held back support in many previous climate efforts.

Imagine, for example, that a near-peer competitor is threatening a key US trade partner in its region (figure 2). A traditional analysis of the situation would analyse the political, military, economic, social, infrastructure and information dynamics between the two nations. By adding a climate lens, leaders can develop an even more comprehensive picture of the operational environment. The more detailed picture can uncover previously hidden relationships in causal factors that can, in turn, show new interventions that can achieve the desired end state.

For example, adding a climate lens might reveal the tension between the adversary’s need for regional legitimacy and its demand for water, which it secures by building dams on shared water sources. The dams severely limit water supplies to neighbouring nations, worsening the impact of shifting rain patterns. With that tension understood, armed forces IO messaging could help influence the regional population to see the adversary’s actions as self-centred and outside international norms.

A climate lens can support operational effectiveness as well. Changes in sea level will significantly alter the number and location of sites suitable for large-scale amphibious attacks. By projecting future sea-level trends, the US armed forces can help partner nations concentrate defences such as anti-ship missiles in areas most vulnerable during the window of attack.

A sole focus on resilience can deter progress

Adding a climate lens to operations can introduce new requirements, new costs and new frictions to military processes. But looking at climate solely as a resilience issue won’t help improve mission effectiveness and may hinder progress on climate goals as well.

Resilience is a necessary goal, of course. Hurricanes and severe storms, for instance, routinely damage coastal armed forces bases, rendering them inoperable for long periods and causing billions in damages. In 2018, Florida’s Tyndall Air Force Base was hit by Hurricane Michael, which damaged or destroyed numerous structures on the base and left hangars shredded and roofless.7 And such damage isn’t limited to coasts; in 2019, floods destroyed a third of Offutt Air Force Base in Nebraska. The reconstruction will take years to complete and is expected to cost nearly US$5 billion.8

This explicit link between adverse weather events and mission assurance has led DoD towards a resilience framework intended to protect its installations and weapons systems against extreme weather, secure supply chains and build a “climate-ready” force.9 The Air Force, for example, has developed a geospatial supply chain risk identification and monitoring (Geo-SCRIM) tool that monitors adverse weather events such as wildfires or hurricanes and alerts organisations in their path.10 DoD’s  2023 budget request includes more than US$2 billion to improve the resilience of armed forces installations, with US$553 million of that intended to help bases weather power disruptions via microgrids and renewable energy and US$322 million to help them survive extreme weather events.11

But while resilience is critical, it shouldn’t be the sole focus of DoD’s climate action. Instead, it should be the first step towards making DoD a climate-forward agency that can use climate change to its advantage.

If climate isn’t a fundamental part of the operational environment, it can be difficult to see sufficient mission benefits to justify the investments needed to scale climate solutions. Consider aviation biofuels, for example. Both the Air Force and Navy are at the cutting edge of biofuel use in jet engines.12 Yet, more than a decade into their efforts, the adoption rate is still slow, largely because biofuels are more expensive than traditional fuels and in shorter supply.13 The expense of biofuel use could be justifiable if they improved mission outcomes, but jets fly just as far and as fast on conventional fuel but at a lower cost and greater ease of access.

The armed forces have produced important climate-related innovations but has seen relatively slow adoption of them. To reduce its reliance on diesel generators for power—and the often-targeted fuel convoys that feed them—the Marine Corps has moved into the forefront of tactical solar power generation. In 2018, the Marines even fully fielded a mobile solar power array designed to power an entire battalion command post.14 In the absence of an operational focus on climate, however, progress has been slow; the programme required nearly a decade to move from first experiments to full fielding.15 Compare this with more obviously operationally relevant tools such as metal detectors. At about the same time as the first battalion-level solar experiments, improvised explosive devices using little or no metal began to emerge in Afghanistan, making their detection extremely difficult.16 But while it took nearly a decade to field the solar experiments fully, it took mere months to get thousands of new combo-metal detectors and ground-penetrating radar units in the hands of troops.17

The clearer the connection between an activity and an operational outcome, the faster organisational processes work. To improve progress on climate projects, DoD must begin to see mission opportunities in climate and embed them in training, planning and acquisition. In a recent speech at the Naval War College, Kristina O’Brien, principal deputy director of the joint chiefs’ Strategic Logistics J-4 organisation, spoke about “operationalising” climate factors: “There are opportunities that go along with these challenges, but very key here is how do we need to be considering this in our operational plans, into our campaign plans and into our logistics plans.”18

Threats and potential innovations both offer motivation

The effort needed to change how DoD creates plans can be significant and benefits to mission effectiveness may not be enough to overcome bureaucratic inertia. In such cases, adversaries’ actions and new innovations both may offer additional motivation.

Adversaries are already adapting

Our adversaries will use whatever leverage is available to achieve purely military goals. Since climate change is an extremely important issue for China’s neighbours and adversaries, for instance, it has become a key factor influencing Chinese decision-making and actions. In 2022, a Chinese influence campaign unsuccessfully attempted to mobilise US protests against an Australian rare-earths mining company planning an expansion in Texas, in an effort to defend Beijing’s dominance of the market. The campaign deployed various social media accounts, some implying they were owned by locals, to claim that the Texas facility would cause environmental damage.19

Yet our adversaries also are vulnerable to climate issues. A recent trade and security co-operation pact between Pacific islands and China was derailed over the island nations’ concern about climate issues.20 From dirty coal plants in Africa to water shortages created by the Belt and Road Initiative, China’s security goals are often complicated by its own actions.

Like any other part of the operational environment, climate is a contested space with both opportunities and vulnerabilities. Keeping climate action outside the operational sphere and limited only to resiliency comes with significant risks. To ignore the military implications of climate change is to cede control of that part of the environment to adversaries.

Armed Forces innovations can catalyse economic transformation, which builds Armed Forces power

Adding a climate lens to military decision-making also can spur economic growth. It can create operational needs such as new algorithms to crunch massive climate data, new materials to reduce corrosion due to sea-level rise and new means of generating power for small teams at advanced bases. The cost-benefit analysis for developing solutions and even completely new technologies for armed forces applications is fundamentally different from that for the commercial sector. As the armed forces works with industry to create these solutions, new breakthrough opportunities can emerge that wouldn’t have been developed by the private sector alone.

In the past, military-specific innovations often have had significant impact on the broader economy. The global positioning system (GPS) is an excellent example. The impetus for early GPS research was the Navy’s need to provide accurate locational information to Polaris missiles aboard constantly moving ships.21 Similar requirements among the Air Force and Army led to the development of GPS in the late 1970s. At the time, commercial industry hadn’t expressed any analogous need.22 Yet, once the technology became commercially available in 1983, it had a transformative impact, spawning new uses and even entirely new industries.23

The economic impact of GPS is hard to overstate. Researchers estimate that it has contributed more than US$1.4 trillion to the US economy alone since its release for public use.24 Given the scope and scale of climate change, climate-related technology may have an even greater commercial impact.

What could defence-driven climate innovations look like?

We’re not suggesting the military invest in climate innovations out of altruism. Creating them is in the military’s best interest, both directly and indirectly—directly, as it provides warfighters with solutions that address important facets of the operational environment and indirectly, by catalysing commercial innovation and giving the military increased national economic power.

For example, extreme weather and rising sea levels are increasing the concrete degradation rate. To keep runways and piers mission-capable, the military is investing in finding innovative solutions to this problem, such as self-healing concrete.25 The annual worldwide cost of metal and concrete corrosion has been estimated at more than US$2.5 trillion—more than 3% of global GDP per year—and any innovation that helps solve the problem could have a massive economic impact.26

But such innovations aren’t limited to resilience. New missions also can spark transformational innovations. For example, rising sea levels may offer increased opportunities for submarine-based intelligence collection along coastlines. Such missions will prioritise stealth above other considerations, perhaps making air-independent propulsion systems (which rely on energy-efficient fuel cells) even more useful than nuclear propulsion in some cases.27 With more investment, such technologies could develop into forms that may provide cheap, clean energy in small packages to the wider world.

When innovations such as these have spilled over to the commercial industry in the past, the impact has been transformational. GPS, the internet, radar, lidar, integrated circuits, touchscreens, artificial intelligence assistants—the list of armed forces innovations that fundamentally transformed commercial industry is lengthy.

And economic growth, in turn, supports armed forces performance. A body of research argues that increased economic power correlates not only with armed forces strength but even success on the battlefield.28 DoD’s investment in climate will continue to pay for itself along several different paths leading to increased mission effectiveness.

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Institutionalising the change

Seeing climate as an inextricable part of the operational environment calls for a significant mindset shift and institutionalising that viewpoint will likely require changes to core DoD processes, including training and education, planning and procurement. Recommended steps along the way include:

Training and education

  • Adjust the training curricula for both officers and enlisted personnel to reflect climate as an inextricable part of the operational environment.
  • Develop wargames with climate-related themes to hone the skills of general and flag officers in identifying scenarios in which climate change may offer strategic opportunities.


  • Revise Joint Publication 5-0 Joint Planning to institutionalise viewing the operational environment through a climate lens along with political, military, economic, social, information and infrastructure. Changing the acronym PMESII to PMESII-C (see figure 2) can succinctly capture this shift.
  • Create an interagency IO working group dedicated to climate themes. Leaders and populations around the world are increasingly sensitive to climate impacts; climate-themed messaging may be increasingly useful in strategically important regions.


  • Identify the climate-related armed forces needs the new innovations can help answer. For example, adding climate impact as a consideration for milestone A decisions in the Joint Capabilities Integration and Development System can help climate-related needs compete with traditional mission parameters such as speed, payload and range.
  • Create a climate innovation fund specifically to fund the research and procurement of innovative climate-related technologies. Such a fund could accelerate the development of new technologies and help DoD establish important working relationships with partners in industry and academia.

To be ready to deter and win wars, the military must be ready for a range of possibilities. Often, that readiness comes at the cost of billions of dollars in new weapons systems. But the changes needed to take advantage of climate change’s impacts on the operational environment often require little more than a new mindset. New curricula, new edits to familiar processes and new tools for collaboration are small changes that can have big results. It’s a step any leader should take for a more resilient and more effective armed forces.

Defence, Security & Justice

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  1. US Department of Defense (DoD), “Statement by Secretary of Defense Lloyd J. Austin III on the Department of Defense Climate Adaptation Plan,” October 7, 2021.View in Article
  2. DoD, Department of Draft Defense Climate Adaptation Plan, September 1, 2021.

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  3. Michon Scott, “Anticipating more activity in the Arctic, NOAA invests in research to advance sea ice forecasting,” National Oceanic and Atmospheric Administration, January 29, 2020.

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  4. See for instance: Neil Shea, “Scenes from the new cold war unfolding at the top of the world,” National Geographic, May 8, 2019; Neil Shea, “A thawing Arctic is heating up a new cold war,” National Geographic, August 15, 2019.View in Article
  5. Abbie Tingstad and Scott Savitz, “U.S. military may need to invest more in Arctic capabilities,” RAND Blog, February 10, 2022.View in Article
  6. See for instance the definition of joint planning in: Joint Chief of Staff, Joint Publication 5-0: Joint Planning, December 1, 2020, pp. xi—xii.

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  7. Magen M. Reeves, “Tyndall AFB continues rebuild effort one year after Hurricane Michael,” U.S. Air Force, 325th Fighter Wing Public Affairs, October 10, 2019. View in Article
  8. K.C. Baker, “How this air force base’s $5 billion reconstruction will ‘protect our people’ amid climate change,” People, April 16, 2020.View in Article
  9. As encapsulated in: DoD, Department of Defense Draft Climate Adaptation Plan.

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  10. Ibid, p. 8.View in Article
  11. Francesco Femia and Caitlin Werrell, “Unpacking the Pentagon’s $3.1 billion climate request,” Center for Climate & Security, May 5, 2022.View in Article
  12. Elizabeth Shogren, “Air Force and Navy turn to biofuels,” NPR, September 22, 2011.View in Article
  13. For cost and capacity limitations on aviation biofuels, see: International Energy Agency, “Are conditions right for biojet to take flight over the next five years?” December 1, 2021; For more on their military uses, see: Associated Press, “US navy launches first biofuel-powered aircraft carriers,” Guardian, January 21, 2016.

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  14. Matt Gonzales, “Corps’ power, water systems are getting lean and going green,” United States Marine Corps, May 4, 2021.View in Article
  15. Ibid; DoD Environment, Safety and Occupational Health Network and Information Exchange (DENIX), “Ground renewable expeditionary energy system (GREENS),” November 2009.

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  16. Joint Improvised Explosive Device Defeat Organization, “Victim operated improvised explosive device (VOIED) recognition guide, Afghanistan,” March 2011.View in Article
  17. Defense Industry Daily, “USMC commits up to $48.6M for Vallon’s hand-held mine detectors,” December 13, 2010.View in Article
  18. U.S. Naval War College, “National security significance of a changing climate: Operationalizing climate security,” March 18, 2022.

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  19. A.J. Vicens, “Chinese influence operation aimed to protect Beijing’s stake in rare earth mining, research finds,” CyberScoop, June 28, 2022.View in Article
  20. Stephen Dziedzic, “China to continue pushing for Pacific Island nations to sign regional trade and security agreement,” ABC News (Australia), May 30, 2022.

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  21. William H. Guier and George C. Weiffenbach, “Genesis of satellite navigation,” Johns Hopkins APL Technical Digest 19, no. 1 (1998).View in Article
  22. Catherine Alexandrow, “The story of GPS,” DARPA: 50 Years of Bridging the Gap, October 20, 2016. 

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  23. Juquai McDuffie, “Why the military released GPS to the public,” Popular Mechanics, June 19, 2017.View in Article
  24. Kathleen McTigue, “Economic benefits of the global positioning system to the U.S. private sector study,” National Institute of Standards and Technology, February 22, 2021.

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  25. Brandi Vincent, “DARPA to develop bio-inspired tech to ‘self-heal’ Pentagon’s deteriorating concrete structures,” FedScoop, June 6, 2022.View in Article
  26. NACE International, “Economic impact,” accessed September 1, 2022. View in Article
  27. K.J. Rawson and E.C. Tupper, “Air independent propulsion,” a chapter in Basic Ship Theory, Fifth Edition (Butterworth-Heinemann, 2001).View in Article
  28. See, for instance: Frank W. Wayman, J. David Singer, and Gary Goertz, “Capabilities, allocations, and success in militarized disputes and wars, 1816–1976,” International Studies Quarterly 27, no. 4 (December 1983) pp. 497–515; Michael Beckley, “Economic development and military effectiveness,” Journal of Strategic Studies 33, no.1 (February 19, 2010) pp. 43–79.

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The authors would like to thank Bruce Chew, Tiffany Fishman, Catherine Foley, and Nicole Cosmann for their insights and thoughtful feedback on the draft. They’d also like to thank the Deloitte Insights staff, and specifically, Ramani Moses and Aparna Prusty, for their support in producing this research.

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