The U.S. military, the government’s largest fuel buyer, is leading the fight against climate change by investing in the “Great Green Fleet” and other ways of cutting dependence on oil and coal, according to a Pew Charitable Trusts report released on Tuesday.

“They’re not having long and protracted debates about whether or not we can afford it … they are marching” into investments in everything from electric vehicles to forming strike groups that run on alternative fuels, said Phyllis Cuttino, director of Pew Environment Group’s Global Warming Campaign.

The report, “Re-energizing America’s Defense,” says the military has found that climate change may lead to domestic and international instability by threatening water and food supplies. In addition, stronger storms caused by emissions could increase the need for humanitarian missions by the military both at home and abroad, which could stretch resources.