Some things are going to change under the new Paris climate deal, including how armed forces around the world will have to manage their substantial carbon output. This even includes the almighty U.S. military, which so far has been exempted from having to even report its emissions, and this despite the fact that the United States wasn't even a signatory to the Kyoto Protocol.
To be fair, this doesn't mean that we're going to see Recon Marines roll around in Chevy Volts or ace pilots soar on gliders any time soon. The new deal doesn't force any country to cut its armed forces emissions, but at least the automatic exemptions are gone and we'll get a clearer picture of what is actually going on, paving the way for a more accurate portrait of each country's carbon outputs and more effective actions.
“If we’re going to win on climate we have to make sure we are counting carbon completely, not exempting different things like military emissions because it is politically inconvenient to count them,” Stephen Kretzmann, Oil Change International’s director told the Guardian. “The atmosphere certainly counts the carbon from the military, therefore we must as well.”
At first, this might sound like something that the Pentagon will hate, but the top military brass has understood for a long time that too many good soldiers get killed (directly and indirectly) to defend fossil fuels, and that in any war, the supply lines that bring fuel to your troops and their machines are one of the most constraining and vulnerable elements in any army, moving slowly and needing to be heavily defended at all times. Anything that decreases fuel use - including to diesel generators, which are used ubiquitously by deployed forces - potentially makes troops safer and more effective.
It's certainly seems likely that a greener world where most countries get their power from renewable sources of energy like the sun and the wind would probably be safer all around, as a lot of geopolitical instability over the past century has arisen from energy-related disputes (mostly for oil and natural gas, but not exclusively).