The historic United Nations Paris climate deal has some unexpected ramifications for American armed forces. The U.S. military, one of the biggest consumers of crude oil in the world, is no longer automatically exempt from tracking or cutting its carbon emissions. If our current or future commander-in-chief dictates that the military shrink its carbon footprint, it might have to start cutting back on the vehicles and equipment that cause the most pollution.

The United States never ratified the Kyoto Protocol, the climate agreement last reached by international leaders. However, it did earn an “opt-out” that allowed the U.S. military to operate without regulating its greenhouse gas emissions. The Paris agreement has removed this exemption and put the ball in the president’s court.

During the first four years of the Iraq War, the military emitted 141 million tons. According to the Guardian, this is figure is the same as putting 25 million cars on the road for a year.

Steven Groves of the Heritage Foundation said that regulating carbon emissions could have deep consequences for the military.

“Lets face it, vast swathes of our military are big carbon emitters — tanks, Jeeps, Humvees, jet planes — and of course much of our navy is not nuclear-powered, so [the Paris agreement] could be used as a trojan horse,” said Groves. “This might be a good opportunity for people concerned with national security to go to Congress and get some type of legislative exemption in the same way as was done during the Kyoto time period.”

On the other hand, Stephen Kretzemann of Oil Change International thinks it’s time to hold all militaries accountable–and that means including the United States.

“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,” Kretzmann said. “The atmosphere certainly counts the carbon from the military, therefore we must as well.”