Militaries are huge energy users whose greenhouse gas emissions (GHG) make a significant contribution to the climate crisis. However, countries do not systematically record and report their military missions, so the real share of this type of emissions remains unclear – this is known as the military emissions gap. The Conflict and Environment Observatory (CEOBS) and the Scientists for Global Responsibility estimate that everyday military activity could be responsible for around 5.5% of global emissions, meaning that if the world’s militaries were a country, they would be the fourth largest emitter in the world.

Furthermore, this 5.5% estimate does not take into account the significant climate impact of armed conflicts themselves. Russia’s invasion of Ukraine prompted the first comprehensive estimate of the climate impact of an ongoing armed conflict, with researchers estimating that the first two years of the invasion caused emissions greater than the annual output of an industrialised country like the Netherlands.

To keep the Paris Agreement promises in reach and limit global warming to 1.5°C-2°C, emissions must be halved by 2030. But governments cannot manage what they do not measure, and climate action trackers like the CCPI cannot analyse what governments do not report. Currently, no government is obliged to report the emissions from their military activity to the United Nations Framework Convention on Climate Change (UNFCCC), so many don’t. A comprehensive data basis is an important first step for measuring progress, promoting informed policy making, and holding countries responsible for their actions.