Sustainable defence

Climate change is one of the great global challenges of our time. Governments, civil societies and industry are urgently working to mitigate climate change and adapt to a warming Earth. 

The Paris Agreement, a legally binding international treaty on climate change, seeks to limit global warming to 1.5°C above pre-industrial levels. Signatory countries are committed to reducing man-made greenhouse gas emissions (GHG) and levels of carbon dioxide. In 2019, the European Climate Law set the goal for the European Union to be climate neutral by 2050.

Many countries have prepared transition strategies for their entire economies. In the defence sector, both the demand side (national governments with the armed forces as end-users) and the supply side (the defence industry) can contribute to the global effort of reducing GHG emissions. A number of European countries have incorporated specific milestones for the decarbonisation of defence activities into their national or military climate strategies (International Institute for Strategic Studies).

Understanding the problem

GHG emissions associated with the broader defence sector are currently not well documented and estimates vary. A recent study estimates the total carbon footprint of the defence sector to be approximately 520 MtCO₂e each year or 1% of global man-made GHG emissions (Roland Berger). This compares with 12% from road transport, and 2% from each the civil aviation and the maritime sectors (Roland Berger, Table C: “Defence vs. other sectors’ emissions”). The European defence sector is estimated to contribute approximately 6% of defence emissions (Scientists for Global Responsibility).

Defence emissions can be broken down as follows:

• Emissions resulting from the production of military equipment (from raw material extraction to final product delivery) and its operation by the armed forces today account for 70% of the total.
• The remaining 30% stems from military facilities and infrastructure. (Roland Berger).

The defence industry contributes to the emissions associated with military equipment production and operation. These can be categorised in ‘scopes’, which cover industry’s own operations (scopes 1 and 2), its supply chains (scope 3 upstream), and the usage of its products by militaries (scope 3 downstream).

It is estimated that for military equipment, manufacturing accounts for 5-10% of the lifecycle carbon footprint (scope 1 and 2), emissions from the supply chain account for 20-30% (scope 3 upstream), and emissions from the operation of the product for the remaining 65-75% (scope 3 upstream; all scope percentage data from Boston Consulting Group internal report 2022).

While there are increasing efforts to reduce the carbon footprint of existing military equipment, the defence industry is also working to reduce the footprint of future products across their lifecycle. To achieve this, industry is improving manufacturing processes and future product design, and working with its suppliers to decarbonise their operations.

The challenge of decarbonising defence

The defence industry does not get a free pass but does face some unique challenges.  Our mission is to provide our armed forces with the capabilities they need to protect citizens and nations.  Measures to reduce GHG emissions must maintain the safety, reliability, and operational performance that European militaries will continue to require from defence products.

Many energy-intensive defence platforms, such as tanks, combat aircraft or naval vessels, are technically complex, requiring many years of engineering design and development. They are planned to be in service for decades while retaining the ability to operate across different geographical regions, with different climatic conditions and infrastructure, and alongside the equipment of our allies. The long lifecycles of these platforms and the diversity of the environments in which they could potentially be deployed make rapid technological evolution difficult and emphasise the need for consideration of future climate impacts at the point of design and manufacture.

Most importantly, defence is a market where national governments play a unique role as sole customers, sponsors, and regulators. We must work in close partnership with our customers to meet the challenge of decarbonisation.

Advancing decarbonisation

There are many cases where technological advancements within the industry are already contributing to decarbonisation. Although decarbonisation is a challenge for Europe’s defence industry and militaries, it has the potential to bring important advantages beyond reducing the impact on the climate. For our armed forces, reduced carbon usage, for example through improved fuel efficiency, simulation-based training, and electrification-enabled silent manoeuvrability, can bring an operational advantage. The use of decarbonisation technologies, like sustainable aviation fuels, can also reduce the strategic dependence on foreign and non-secure energy supply sources.

The way ahead

The European defence industry must fulfil its primary objective of meeting the demanding military capability requirements of our armed forces while reducing GHG emissions. Despite the challenges, the European defence industry is determined to play its part. We aim to:

• Reduce GHG emissions from industry’s own operations (scopes 1 and 2), in accordance with the Paris Agreement, aligning with a 1.5-degree pathway. Major European defence companies have quantified carbon reduction targets to be achieved within the next decade. A review of major European defence companies’ published data indicates more than 10% reduction in operational carbon emissions since 2020. The specific ambitions and reduction targets of individual companies are publicly available through company websites.
• Collaborate across the intricate and co-dependent supply chain to minimise GHG emissions (scope 3 upstream). Companies of all sizes are developing best practice standards and tools to quantify and address carbon emissions. The work is being driven across number of national defence industry associations and international forums (e.g. ASD, IAEG) and through adopting and adapting initiatives from other sectors.
• Address the full life cycle of military products and systems (scope 3 downstream), including emissions associated with production, use and disposal. This includes designing products for longevity, repairability, circularity and recyclability to minimize lifecycle emissions.  The concept of eco-design is relatively new for defence manufacturing and needs to be further evolved to provide the required understanding and evolve the application of the principles of eco-design at the earliest stages of product development.
• Use technology and innovation to drive decarbonisation of military platforms and products. While there are specific operating parameters for military equipment, there is potential for innovative developments in the civil space to be adapted for military use (see examples in Table 1).
• Implement circular economy principles to reduce waste and emissions through strategies like remanufacturing, reuse, and recycling of equipment and materials.
• Improve transparency, reporting and disclosure of both climate impacts of the defence sector and progress against key milestones and communication of research development and technological advancement.

The challenge demands a collective and collaborative effort. As these developments are rolled out across Europe, coordination among all relevant stakeholders is essential to ensure a common approach to technologies, infrastructures, and military requirements.

What is ASD doing?

ASD has set up a Taskforce for Climate & Defence, gathering high-level sustainability experts from members across Europe to discuss and align positions on challenges, limitations and contributions of the industry regarding the decarbonisation of defence.