Greening Defence: The UK Armed Forces Strategic Approach to Climate Change

British troops train to fight in Norway's forests during Exercise Trident Juncture. Courtesy of Ed Low/Defence Imagery

The Ministry of Defence’s Climate Change and Sustainability Strategic Approach outlines an ambitious vision as to how Defence will achieve national environmental targets. But does the document provide the foundations for reducing Defence’s carbon emissions by 2050, and does the MoD estate hold the answer to success?

Published in March 2021, the Climate Change and Sustainability Strategic Approach (CCSSA) aimed to outline how the UK Armed Forces can tackle climate change and realise a more sustainable future. The document was a formal response to an internal report published by Lieutenant General Richard Nugee, then Director of Climate Change and Sustainability. For a 15-page publication, the CCSSA provides a thorough summary of Nugee’s findings and outlines Defence’s strategic ambitions for 2050. It identifies areas for change and offers an initial action plan for each, delivering transformation over three epochs. Working collaboratively with government, industry, academia and international partners, the CCSSA is designed to ensure that Defence can reduce its emissions to meet national Net Zero Strategy requirements.

The CCSSA: An Overview

On first appearance, the CCSSA is admirably ambitious and all-encompassing in scope, making a vast range of commitments and promises. The epochs appear sensible and steady: setting the foundations (2021–25), minimising and fitting for the future (2026–35), and harnessing the future (2036–2050). However, while the CCSSA provides the vision for a greener, more eco-friendly Defence, it is somewhat light on detail as to how these aims will be achieved, particularly in terms of finance; much of the detail from Nugee’s report is not included. For the CCSSA to be successful within the mandated deadlines, Defence requires a clearly defined strategy, including specified prioritisation across epochs.

Of key concern is an emphasis on industry to innovate on behalf of Defence. While Defence has avidly adopted Nugee’s instruction to become a ‘fast follower of industry’, there is a danger for this concept to be misconstrued. As a fast follower, Defence must adopt existing green technologies now, such as ground-source heat pumps and solar panels; concurrently, it must pay close attention to longer-term eco-R&D by industry, ready to react to military-relevant technological breakthroughs. This means the military must remain flexible to introduce and integrate new technologies as they evolve. The eco-technology industry is still relatively small and cannot respond to Defence’s requirements without upscaling. The assumption that industry will militarise green technologies without financial investment from Defence is flawed. The niche skillset and technical workforce required for R&D will be limited in availability; the military will find it challenging to compete financially with the civilian sector to attract the necessary expertise. Ultimately, green technologies cannot be delivered on a shoestring budget. The CCSSA’s reliance on industry represents a key vulnerability within the approach.

Is Defence Jumping on the Greenwashing Bandwagon?

The establishment of a Climate Change and Sustainability (CC&S) directorate shows Defence is beginning to take the environment seriously. However, the gesture appears skin-deep. The small, predominantly civilian directorate is led by senior civil servant James Clare and encompasses a wealth of environmental expertise. Military personnel are notable by their absence – three posts exist but remain unfilled – reflecting either a lack of suitable individuals, or worse, a lack of prioritisation. Furthermore, the department seems to have little authority to hold the Services to account; without appropriate resourcing, the utility of the CC&S directorate is constrained. This issue is particularly problematic when considering Defence’s ability to tackle the relatively ill-defined area of environmental sustainability.

While all Defence projects are to be viewed through an ‘environmental lens’, the reality is that CC&S has yet to become a critical requirement against which the success of projects can be measured. The vision of the CCSSA has yet to be fully embraced by Defence, particularly at the middle and upper echelons, and consequently, the environment remains a consideration – to some even an imposition – rather than a requirement.

Given these complicated power dynamics, Defence should look for a quick win to justify CC&S as a concept that is here to stay and jump-start environmental change within the institution. In this instance, the MoD estate may hold the key.

Greening the MoD Estate

While each service will seek to reduce carbon emissions in its own sector, the MoD estate offers the greatest short-term potential given that domestic infrastructure is the third largest carbon-emitting sector in the UK. Promisingly, both the MoD estate and its uses are broad, and a variety of approaches can be adopted to reduce emissions.

The most understood solution lies in renewable energy such as solar and wind, where industry already possesses cost-effective technology. The British Army has already invested £200 million in Project Prometheus, which estimates savings of 2,000 tCO2e (tonnes of carbon dioxide equivalent) annually across four sites. Perhaps of more interest to financiers, the project has the potential to make £1 million in efficiency savings per year. Through communicating financial benefits in terms of whole-life costs – that is, the idea of spending now to save in the long term – the Services may achieve greater senior-level buy-in for CC&S. Money talks, and is often more attractive than a moral responsibility to reduce ‘X million tonnes of carbon emissions’.

A further opportunity for quick gains exists in the renovation of an aging housing stock and retrofitting it with greener technologies. Examples such as draughtproofing houses or modernising heating systems improve energy efficiency, reduce the usage of gas and electricity and decrease the need to construct new accommodation. This last point is key in reducing carbon emissions; it is estimated that 51% of the lifecycle carbon from a typical residential development is emitted during construction. As an added incentive, upgrading accommodation may address growing complaints about sub-standard housing and improve morale (the Army recently reported that only 49% of soldiers were satisfied with their standard of accommodation). Consequently, the MoD should re-evaluate its approach of managed decline of infrastructure by reinvesting in existing facilities.

Finally, not all projects involve new technology. The rewilding of some parts of the MoD estate – that is, the restoration of land to its natural state – has already proven popular with the general public. Rewilding offers benefits for biodiversity, water quality, health and carbon sequestration while reducing flood risk: Pirbright Ranges is often held up as a prime example.

Though the proposed changes to the estate are relatively low-key compared to headline-grabbing projects such as vehicle electrification, they utilise existing technology, meaning they are relatively cheap to implement and will reduce emissions quickly. If the methods described were rolled out en masse across the MoD estate, the environmental impact would be significant, rapidly reducing carbon output and providing financial savings with minimal impact on Defence output. In contrast, it will take time to develop suitable technology for the electrification of operational platforms, and the rollout will be financially expensive; Defence can begin to transform its estate instantly through the utilisation of existing methods that do not require military conversion. This is a cost-effective and efficient approach to achieving climate change and sustainability targets.


Responding to the release of the Chancellor’s budget on 27 October 2021, Sam Alvis of the Green Alliance spoke on the relative roles of the state and private sector with regards to climate change, warning that ‘the fiscally responsible approach is to invest now rather than facing huge risks to the economy and environment later’; this statement rings true for the Armed Forces. While the CCSSA offers a good starting point, the Integrated Review felt like a missed opportunity to place climate change at the front and centre of Defence. With the first year of the first epoch having passed, the MoD needs to prioritise where and how it wants to reduce emissions, including a clear strategy and a detailed road map for implementation, if success is to be achieved.

Efficiency and operational effectiveness will depend on the innovation and foresight of previous epochs. (CCSSA, p. 20).

In the short term, reducing carbon emissions across the MoD estate should be prioritised, given readily available technology compared with the current technological limitations on electrification of operational fleets. The latter must be pursued on a longer-term basis, building upon progress within the civilian sector and allowing Defence to become a ‘smart customer’ rather than purely a ‘fast follower’. Finally, if climate change is so important to Defence, a cultural change may be required, allowing appropriate prioritisation to target marginal, cumulative gains as part of a long-term vision.

The next commentary in this series will explore the ways in which the British Army intends to reduce its carbon footprint.

The views expressed in this Commentary are the authors’, and do not represent those of RUSI or any other institution.

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Dr Sarah Ashbridge

Affiliate Expert

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Lieutenant Colonel Alistair Beard

Former Army Visiting Fellow

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