Military GHG emissions data reported by Parties to the UNFCCC has been examined to gauge its status, transparency and consistency.

Under guidelines published by the Intergovernmental Panel on Climate Change (IPCC), military fuel use should be reported under IPCC category 1.A.5 (Other, not elsewhere specified). This category includes all mobile fuel consumption, such as ships, aircraft and road vehicles. It also includes all stationary fuel consumption, such as heating buildings on military bases.

GHG emissions should be reported at the most disaggregated level of each source, but current guidelines allow aggregation to protect military information. But if they are aggregated, this means that emissions from military mobile and stationary fuel use cannot be properly distinguished in UNFCCC reporting.

The reporting and review requirements for UNFCCC Annex I and Non-Annex I parties vary. UNFCCC Annex I parties are classified as industrialised countries and economies in transition, with a requirement to submit an annual national inventory report (NIR).

UNFCCC Non-Annex I parties are required to submit their first National Communications (NC) within three years of entering the Convention, and every four years thereafter. All Non-Annex I parties are required to submit a national inventory of anthropogenic emissions by sources as part of their NC and biennial update reports.

We have reviewed and listed UNFCCC data reported under category 1.A.5 only. According to the IPCC guidelines, memo items to summary tables also allow military fuel under international bunkers and multilateral operations to be included, although their emissions are not included in national totals. Where applicable, commentary notes have been included. This may include commentary on where military data is stated as being reported elsewhere, and under categories other than 1.A.5.

Annex 1 parties Iceland, Liechtenstein and Monaco were not included in the map data due to them reporting very low or no military expenditure.

Military use of the greenhouse gases sulphur hexafluoride (SF6) and perflurocarbons (PFCs) – as reported under category 2.G.2a – is not included in the map data. With the exception of Japan and the United Kingdom reporting 49.42 kt CO2e in total, no disaggregated military data on emissions from SF6 and PFC use was reported to the UNFCCC for 2021.

The map covers all Annex I countries and those non-Annex I countries that rank in the top 60 according to estimates on military expenditure from SIPRI for 2022. We have not included countries for which estimates on military expenditure are unavailable. SIPRI do not have recent estimates on military expenditure for the following countries: Afghanistan, Cuba, Djibouti, Eritrea, North Korea, Laos, Libya, Sudan, Syria, Turkmenistan, United Arab Emirates, Uzbekistan, Viet Nam and Yemen. These countries are excluded from the ranking of global military expenditure.

Myanmar dropped out of the top 60 during the present period, whereas military spending data for Lebanon became available.

The military expenditure data for Argentina, Egypt, Ethiopia, Iraq, Myanmar, Russia, Venezuela and Zimbabwe is reported by SIPRI as highly uncertain. Figures for Bahrain, China, Kyrgyz Republic, Lebanon, Mozambique, Oman, Saudi Arabia, Serbia, Tajikistan, and Ukraine are all SIPRI estimates.

Taiwan Province of China does not report to the UNFCCC and is not included in the map data but is ranked 21st for global military expenditure.

GDP data (2022) from the World Bank has been used to estimate a country’s military expenditure as a percentage of gross domestic product. Only GDP data for 2021 was available for Lebanon (as of 26-10-2023).

We have classed the accessibility of military fuel data reported to UNFCCC as good, fair, poor or very poor. In some cases, military data is ‘included elsewhere”, rather than under 1.A.5 as requested under IPCC guidelines. Where applicable, commentary notes have been included.

Current UNFCCC reporting requires only provision of military fuel use data, which will not account for all military GHG emissions. We have graded the gap between UNFCCC reported data and a broad estimate of the military carbon footprint, which includes the military supply chain. A military carbon footprint (MCF) can be estimated based on the methodology developed for estimating a global military carbon footprint. However, given the limitations in applying the assumptions used in this methodology for an individual country, an estimate of the military carbon footprint is not listed for each country, at this stage.^[1] Instead, an indication of the gap between data reported to the UNFCCC and a broad estimate of the military carbon footprint, is given as an overview under the following categories:

^[1] The methodology for a global military carbon footprint is based on the number of military personnel, assumptions on the GHG emissions per military head and on the ratio of stationary to mobile GHG emissions.

• Very significant gap – MCF likely to be >10 times higher than data reported to the UNFCCC
• Significant gap – MCF likely to be >5 times higher than data reported to the UNFCCC
• Gap – MCF likely to be >2 times higher than data reported to the UNFCCC
• Minor gap – MCF likely to be higher than data reported to the UNFCCC
• No gap identified
• No comparison possible – no UNFCCC data or UNFCCC includes other sources

Some countries do estimate and report GHG emissions, but this typically covers energy use at military bases and fuel use from the operation of military equipment only. Where found, links to in-country reporting of military emissions by government or third parties have been included. It is encouraging that some countries have begun to report GHG emissions, but scopes vary. It is important that militaries report emissions using consistent, unambiguous, transparent, and robust data collection methodologies.  The framework for military GHG emission reporting is a useful starting point for such work.

The UNFCCC data that we have collated and analysed for the map is available as a Google Sheet here, and is based on reported emissions in 2021. This will be updated annually. Previous datasets are available here: 2022 (reporting for 2020) and 2021 (reporting for 2019).