Comment: Military emissions must be reported

Emissions from the world’s armed forces must be counted and reported, argue Oliver Heidrich, Oliver Belcher and colleagues in a Comment article in this week’s Nature. The authors highlight that the US and UK armed forces emit as much carbon dioxide per capita as many carbon-intensive countries. They contend that military emissions must be officially recognized and accurately reported in national inventories, and that military operations need to be decarbonized.

The military sector’s share of global greenhouse-gas emissions is estimated to be around 1–5% — comparable to emissions from the aviation and shipping industries. However, militaries have been left out of international agreements to declare emissions since the 1997 Kyoto Protocol, on the basis of preserving national security. A lack of published data makes it hard to estimate totals, and only a handful of forces — including those of the United Kingdom and United States — have published strategy documents on climate action.

Also missing are accurate methodologies for calculating emissions from military activities. For example, recording is near impossible in hostile, fast-changing or insecure locations.

On the basis of available fuel-use data, the authors note that US forces alone — the world’s largest in terms of expenditure — emit more greenhouse gases than many countries, including Peru, Singapore and Switzerland. If it were a nation, the US military would have the highest per-capita emissions in the world (at 42 metric tonnes of CO2 per staff member).

Heidrich and co-authors suggest that the true total could be even higher: factoring in other energy supplies, raw materials, supply chains and equipment manufacturing could drastically increase emissions estimates. Emissions from warfare would add even more. Researchers need to calculate this to understand how armed conflicts impact the climate and to help countries to chart low-carbon recovery pathways. “A standardized methodology and comprehensive assessment framework for greenhouse gas emissions, including emissions embedded in products across their life cycles, are needed”, the authors conclude.

This press release refers to a Nature Comment piece, not a Nature research paper or article. Comment pieces are topical, authoritative Op-Eds pertaining to scientific research and its ramifications.