The world’s militaries produce at least 5.5% of greenhouse gas emissions – more than the total footprint of Japan – according to one 2022 estimate. But no country is required to provide data on military emissions thanks to successful lobbying by the US at the Kyoto conference in 1997. Leaders removed the exemption in 2015 but made reporting military emissions optional.

Increased militarization harms climate-affected countries in other ways, too, the researchers say. For instance, they found that Nato members are currently selling arms to 39 of the 40 most climate-vulnerable countries; 17 of which are already in armed conflict.

“It’s a real perversion: rather than providing support for communities we are actually making the situation more dangerous and more unstable,” said Buxton.