Royal Air Chief Sir Mike Wigston discusses how the service is considering using a common jet fuel standard and his ambitious goal to become carbon neutral.

The United Kingdom has legislated for the country to meet the target of the Paris Agreement on climate change, reducing national greenhouse gas emissions to net zero by 2050. Prime Minister Boris Johnson is personally committed to achieving this. The U.K. has an ambitious national plan to make the necessary transformations to energy usage across the private and public sectors. The Ministry of Defence is the largest-single contributor to greenhouse gas emissions within the U.K.’s central government, responsible for half of the total.

With the U.K. hosting the United Nations Climate Change Conference, also known as COP26, in November 2021, the MoD has published its “Climate Change and Sustainability Strategic Approach,” a blueprint for military adaptation to climate change. If there is a country with a more developed strategy to adapt its military to adapt to climate change, we are unaware of it here at the International Institute for Strategic Studies.

The strategy recognizes that climate change — especially the increasing number of extreme weather events, rising sea levels and desertification — is already acting as a potential accelerator of insecurity and armed conflict, both within and between states in regions important to U.K. security. IISS is already seeing this in Somalia and the Sahel.

The MoD believes this will not only increase demands for international and domestic humanitarian assistance as well as disaster relief missions, but will also have negative effects on U.K. bases and deployed forces at home and abroad, such as troops, ships and aircraft deployed in the Gulf.

The strategy declares that U.K. forces must become far less dependent on fossil fuels. It outlines an incremental approach in attempting to address and manage the challenges faced. In the near term (the next five years), actions include cataloging emissions and identifying reduction targets, with the focus on the defense estate: barracks, docks, airfields and training areas. The British intend not to purchase carbon offsets for their forces, but to compensate from unavoidable emissions by capturing carbon for themselves.

The goal for 2026-2035 will be to “reduce emissions significantly” using existing and emerging technologies to cut carbon output. In the long term, from 2036-2050, the ministry will look to “novel technologies” to further reduce emissions. This recognizes that many current “green” technologies are not yet mature enough to apply in military equipment, such as fighter jets and heavy armored vehicles.

For example, the Boxer armored vehicle is entering service with a diesel engine and conventional transmission, so a significant reduction in emissions would not be cost-effective before the vehicle’s midlife upgrade. This argues for introducing new technologies as they mature and as existing equipment is upgraded.

The MoD intends to adopt a “fast follower” approach, leveraging carbon-reduction technology under development by the civil sector, along with measures specific to the military. For example, the strategy assesses that across land, maritime and air domains, robotic and autonomous systems will, by virtue of having no crew aboard, have lower emissions than their inhabited equivalents.

Military aviation is responsible for about two-thirds of the MoD’s fuel consumption. British military aircraft have been authorized to use up to 50 percent sustainable fuel and are researching how to achieve 100 percent consumption of sustainable fuel. The Royal Air Force aims for its next basic training aircraft to be carbon neutral. The RAF also plans to make much greater use of synthetic environments to reduce training flights. This should reduce consumption of aviation fuel. The service has ambitious plans for medium- and long-term goals regarding carbon emissions, including aiming to have a carbon neutral estate by 2040.

The British Army is erecting solar panels on its bases, planting 2 million more trees on its estate and is experimenting with hybrid electric drives on Jackal wheeled scout vehicles. The Army chief, Gen. Mark Carleton Smith, has publicly stated that unless the Army’s values are seen to embrace climate security, it will have difficulty recruiting young British people, many of whom care greatly about the climate.

The Royal Navy shows similar enthusiasm and claims that its recently launched patrol boats are its most climate-efficient vessels in its fleet.

The British plan depends on funding decisions to be made over the next 15 years. While the recent increase in defense-related research and development funding will help, many of the financial decisions will have to made in the 2026-2035 period. Key factors influencing these decisions will be how the U.K. economy recovers from the impact of the COVID-19 pandemic and the U.K.’s wider national energy transformation.

There are risks that some military personnel may worry that measures to make equipment “green” could reduce performance, especially against adversaries that choose to retain older equipment. Changing attitudes and culture across the armed forces could be a considerable challenge. However, others argue that there is not necessarily a trade-off between environmental credentials and operational effectiveness, for example arguing that “green means lean” for military logistics.

These are challenges shared by many armed forces globally, especially those whose governments intend to achieve the net-zero emissions target by 2050. There is much that many defense ministries and armed forces could learn from the U.K.’s policy and plans for military climate adaptation.

Retired Brig. Ben Barry is a senior fellow for land warfare at the International Institute for Strategic Studies.

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