The US military is one of the largest consumers and emitters of carbon-dioxide equivalent (CO2e) in history, according to an independent analysis of global fuel-buying practices of a “virtually unresearched” government agency.

If the US military were its own country, it would rank 47th between Peru and Portugal in terms of annual fuel purchases, totaling almost 270,000 barrels of oil bought every day in 2017. In particular, the Air Force is the largest emitter of greenhouse gas emissions and bought $4.9 billion of fuel in 2017 – nearly double that of the Navy ($2.8 billion).

Experts detail in the journal Transactions of the Institute of British Geographers DLA-E’s operations, supply chain, bureaucratic practices, and physical infrastructure, arguing that the military must confront their overuse of fuel consumption and emission in order to battle global warming.

"The US Military has long understood it is not immune from the potential consequences of climate change – recognizing it as a threat multiplier that can exacerbate other threats – nor has it ignored its own contribution to the problem,” said report co-author Patrick Bigger in a statement.

"Yet its climate policy is fundamentally contradictory – confronting the effects of climate change while remaining the largest single institutional consumer of hydrocarbons in the world, a situation it is locked into for years to come because of its dependence on existing aircraft and warships for open-ended operations around the globe."

To analyze the US military’s “carbon boot-print”, a team of British researchers analyzed records of bulk fuel purchased by the US Defense Logistics Agency – Energy (DLA-E) obtained using Freedom of Information Act requests. The DLA-E is a sub-agency within the Defense Logistics Agency that is primarily responsible for supplying petroleum and other hydrogen-based fuels to the US military, making it a powerful actor in the global oil market.

The authors say their work underscores the importance of understanding the logistical processes behind the world’s largest institutions in order to determine how they contribute to global environmental change.

"Our research demonstrates that to account for the US military as a major climate actor, you must understand the logistical supply chain that makes its acquisition and consumption of hydrocarbon-based fuels possible,” said co-author Oliver Belcher. "How do we account for the most far-reaching, sophisticated supply chains, and the largest climate polluter in history? While incremental changes can amount to radical effects in the long-run, there is no shortage of evidence that the climate is at a tipping point and more is needed."

Another analysis of similar data earlier this month suggests the US military would be the 55th largest contributor of GHG if it were considered a nation.

The US military is unlikely to change its dependence on fossil fuels given its role in “everywhere war”, a concept of perpetual presence around the world that results in a need for constant mobility, note the researchers. The life-cycles of military aircraft and warships that use hydrocarbon-based fuel only further consumption practices.