US Military’s Clean Energy Initiatives

The US Department of Defense (DoD) has been fast-tracking clean energy advancements to bolster military safety, ensure energy security and cut costs. The 2011 Pew Charitable Trusts report, 'From Barracks to the Battlefield: Clean Energy Innovation and America’s Armed Forces', noted a 200 per cent surge in DoD clean energy investments from US$ 400 million to US$ 1.2 billion between 2006 and 2009.1

The US military’s efforts are geared towards addressing the impact of climate events on military infrastructure. The US military is also developing green fuels given that it is the largest institutional consumer of energy. These efforts also anticipate new security threats related to climate change, such as resource scarcity, migration and armed conflicts.2

The US Army's Climate Strategy released in 2022 aims for a resilient and sustainable force, addressing climate change through mitigation and adaptation measures in line with modernisation. Goals include a 50 per cent GHG reduction by 2030, net-zero emissions by 2050, given security implications of climate change. The Army plans to aim for carbon-pollution-free power for critical missions by 2040. The US Army intends to integrate climate change mitigation into land management decisions, and incorporate the latest climate and environmental science into deployment choices.3

Similarly, the US Navy's Climate Action 2030 plan prioritises preserving global naval dominance, establishing a climate-resilient force for national security, and improving military operations by addressing climate change impacts to enhance force capability and fortify systems, installations, and the well-being of personnel. It recognises climate success as crucial for mission success.4

The US Department of the Navy is also leading advanced battery research through the Federal Consortium for Advanced Batteries along with Department of State, Energy, Commerce and others to reinforce US industrial base. It seeks to upgrade the Marine Corps vehicle fleet for fuel efficiency, and commits to deploying nature-based solutions for shoreline protection. Energy resilience is a top priority, with cyber-secure microgrids and advanced technologies supporting critical missions, emphasising carbon pollution-free power and long-duration battery storage. 5

As for the US Air Force, Edwin Oshiba, the Assistant Secretary of the Air Force for Energy, Installations, and the Environment, emphasised that the climate plan and energy initiatives are driven by the goal of enhancing combat capability. The focus is on addressing challenges arising from the impacts of climate change. The Air Force aims to transition its entire non-tactical vehicle fleet to zero-emission vehicles by 2035.6 The Department of the Air Force is committed to prioritising infrastructure and facility modernisation, developing a climate-informed workforce, improving logistics and supply chain practices, reducing operational energy intensity, and incorporating alternative energy resources.7

The primary reason for shifting to renewables is the military's vulnerability due to reliance on fossil fuels. US Secretary of Defense James Mattis’s 2006 ‘Future Fuels’ document therefore urged the Pentagon to break free from fossil fuel limitations.8 In April 2008, President George W. Bush mandated a reduction in fossil fuel reliance, aiming for 25 per cent renewable energy in military facilities by 2025.9

The US military emphasises that their climate actions align with the central goal of winning wars. Ray Mabus, former US Navy Secretary stated that the move to alternative fuels in the Navy and Marine Corps aims to enhance combat effectiveness.10 In 2023, Paul Farnan, the Principal Deputy Assistant Secretary noted that increased renewable energy production and long-term battery storage at Army bases can help tackle the climate change challenge and enhance the resilience of installations furthering the military forces' capabilities.11

With the Pentagon leading progressive energy initiatives and backing renewable energy research, the US military seeks to transform climate change from a threat multiplier to a force multiplier, enabling the US military to operate more effectively abroad for extended durations.12

Assessment

The Scientists for Global Responsibility (SGR) notes that global military carbon footprint contributes around 6 per cent of global greenhouse gas emissions.13 The US military is a leading emitter of greenhouse gases globally. From 1975 to 2022, its yearly emissions averaged 81 million metric tons of greenhouse hydrocarbons, surpassing the output of many nations. In fiscal year 2021, the U.S. Department of Defense reported its emissions at 51 million metric tons of carbon dioxide.14   A 2019 study estimated that the Pentagon's greenhouse gas emissions amounted to 59 million tonnes, surpassing the combined emissions of Denmark, Finland and Sweden in 2017.15

Military decarbonisation though is challenging due to high energy needs of militaries worldwide. A global shift to 100 per cent renewables could require significant demilitarisation.16 Further, strategies aimed at reducing military emissions lack clear links to broader environmental goals.17 Activists note that wealthy nations pursuing green energy goals by exploiting resources elsewhere may intensify global disparities, risking inequality in energy resource control.18

The conflict in Ukraine has also highlighted the role of energy in global security. Post the Russian invasion of Ukraine, Western policymakers are speeding up energy transitions to bolster security and cut Moscow's energy earnings through renewables and reduced consumption. Clean energy is seen as crucial for ‘security of supply’ and reducing dependence.19

Globally, the incorporation of emission reduction into defence strategies is limited, creating potential gaps as nations pursue climate goals at different rates within their armed forces. The interdependence of the fossil fuel and military-industrial complex in the extractive economy model raises concerns. The idea of low-carbon warfare raises concerns about potential impacts on conflict engagement. In essence, striving for low-carbon warfare could prolong the use of military force in a net-zero future.

Despite extensive investment in clean energy initiatives and strategies focused on enhancing readiness and reducing environmental impact, concerns persist about the underlying nature of military actions, their link to broader environmental goals, and the potential implications on global politics, economy, and security.

Views expressed are of the author and do not necessarily reflect the views of the Manohar Parrrikar IDSA or of the Government of India.

• 1. “From Barracks to the Battlefield: Clean Energy Innovation and America’s Armed Forces”, PEW, 21 September 2011.
• 2. Lorah Steichen and Lindsay Koshgarian, “No Warming, No War”, National Priorities Project, Institute of Policy Studies, 2020.
• 3. “United States Army Climate Strategy”, Department of the Army, United States of America, February 2022.
• 4. “Climate Action 2030”, Department of the Navy, United States of America, May 2022.
• 5. Ibid.
• 6. Robert K. Ackerman, “Efficiency Fuels Airforce Climate Action Plan”, Signal, 31 March 2023.
• 7. “Climate Campaign Plan”, Department of the Air Force, United States of America, July 2023. 
• 8.  “Future Fuels”, Naval Research Advisory Committee Report, United States of America, April 2006.
• 9. Sean Mowbray, “A Tale of Two Policies: Climate Change, Trump and The US Military”, Mongabay, 17 January 2018.
• 10. “U.S. Navy Deploys ‘Great Green fleet’ in Bid to Reduce Military Energy Use”, Environmental and Energy Study Institute, 22 January 2016.
• 11. “Top Climate Change Execs to Watch in 2023: DOD’s Paul Farnan”, Washington Exec, 21 June 2023.
• 12. Sanjay Chaturvedi and Timothy Doyle, Climate Terror - A Critical Geopolitics of ClimateChange, New Security Challenge Series, 2015.
• 13. “How Big Are Global Military Carbon Emissions”, SGR, 8 July 2023.
• 14. “Fellow Who Measures Pentagon’s Carbon Footprint Wins Grawemeyer World Order Price”, Balliol College, Oxford, 6 December 2023.
• 15. Nick Buxton, “A Primer on Climate Security”, Transnational Institute, October 2021.
• 16. Michael J. Albert, “The Global Politics of the Renewable Energy Transition and the Non-substitutionality Hypothesis: Towards a ‘Great Transformation’”, Review of International Political Economy, Vol. 29, No. 5, 2022, pp. 1766–1781.
• 17. Alex Senchyna, “Greenwashed Imperialism: How Global Wars are Fueling Climate Change and Why Green Military Technology Will Not Solve It”, Spheres of Influence, 6 August 2022.
• 18. Lorah Steichen and Lindsay Koshgarian, “No Warming No War”, no. 2.
• 19. Duncan Depledge, “Low-Carbon Warfare: Climate Change, Net Zero and Military Operations”, International Affairs, Vol. 99, No. 2, 2023, pp. 667–685.