Amongst all greenhouse gas emitters globally, a single U.S. organization stands out, leading the pack.
In a world where climate change poses a significant threat to global security, the US Department of Defense (DoD) has acknowledged the need to address the environmental impact of its operations. A new study published in the journal PLOS Climate explores ways to reduce the energy consumption of the US military, a sector that generates more CO2 than most countries, despite a decrease from 76 million metric tons in 2010 to 55 million by the end of the decade.
To mitigate the US military's significant impact on climate change, four key strategies have been identified:
1. **Reduce Military Spending:** Studies show that decreasing defense spending can greatly reduce greenhouse gas emissions. A gradual annual reduction of around 6.5% in military expenditure could yield energy savings equivalent to the total usage of a small country or US state.
2. **Optimize Energy Usage and Invest in Renewables:** By optimizing how energy is used and investing more in renewable energy sources, the DoD can cut carbon emissions, improve energy resilience, and reduce dependence on fossil fuels.
3. **Target Hard-to-Abate Sectors like Aviation:** Military aviation is a major contributor to the carbon footprint and is difficult to decarbonize. Reducing the scale of aviation operations is critical, which could be achieved by cutting unnecessary flights and investing in research into sustainable aviation fuels and alternative propulsion technologies.
4. **Enhance Energy Security and Resilience Through Advanced Systems:** Military bases increasingly use natural gas-powered combined heat and power (CHP) systems and microgrids to improve resilience and reduce emissions. These systems help maintain critical operations during grid outages and extreme weather, demonstrating that clean energy solutions can align with national security interests.
The table below provides an overview of these strategies and their impacts:
| Strategy | Impact on Energy Use and Emissions | Notes | |---------------------------------|-------------------------------------------------|--------------------------------------------------------| | Reduce Military Spending | Significant cuts in energy use across all sectors | Political challenges but effective for large-scale reduction[1][3] | | Energy Optimization & Renewables| Cuts emissions, improves operational efficiency | Enables resilience and cost savings[2][4][5] | | Scale Back Aviation Operations | Essential for cutting hard-to-abate emissions | Requires operational changes and long-term tech R&D[3] | | Advanced Energy Systems on Bases | Enhances energy security and lowers carbon footprint | Uses natural gas CHP, microgrids for reliability[5] |
While these strategies offer promising solutions, they face challenges. Global military spending is currently rising, and cutting budgets is politically difficult given security concerns. Decarbonizing military aviation remains a technological challenge. However, framing energy reductions as both a climate and national security imperative could facilitate progress.
It is important to note that the US spends significantly more on its military compared to countries like China and India, which have more soldiers but require less energy to maintain. Between 2010 and 2019, the US armed forces emitted 636 million metric tons of CO2. The biggest carbon emitters are energy production, agriculture, transportation, and manufacturing, not just the military.
As the world's military expenditure rose by 9.4 percent in 2024, marking the steepest annual rise since the end of the Cold War, it is clear that sustainability must become part of the mission for global security to be achieved. By combining budget adjustments, energy efficiency measures, renewable integration, and technology innovations, the US military can substantially reduce its carbon footprint and help mitigate climate change without compromising its strategic capabilities. Sustainability is not only an environmental concern but also a matter of national security.
- Addressing climate change necessitates a focus on reducing military spending, as studies indicate that decreasing defense expenditure can significantly reduce greenhouse gas emissions.
- Optimizing energy usage and investing in renewable sources can help the US Department of Defense cut carbon emissions, improve energy resilience, and reduce dependence on fossil fuels.
- Strategies for tackling hard-to-abate sectors like aviation involve reducing the scale of operations and investing in research, such as sustainable aviation fuels and alternative propulsion technologies.
- Enhancing energy security and resilience through advanced systems, like natural gas-powered combined heat and power (CHP) systems and microgrids, can maintain critical operations during grid outages and extreme weather.
- The alignment of clean energy solutions with national security interests is demonstrable through the use of natural gas CHP, microgrids, and other advanced energy systems on military bases.
- Sustainability should be incorporated into the mission for global security, as the US, despite spending significantly more on its military compared to countries like China and India, emitted 636 million metric tons of CO2 from its armed forces between 2010 and 2019.
- With the world's military expenditure rising in 2024, it is crucial to prioritize sustainability within the military sector to achieve global security, by combining budget adjustments, energy efficiency measures, renewable integration, and technology innovations.
