The Pentagon’s Outsized Part in the Climate Fight

Photo DigitalGlobe via Getty Images

A satellite image of the Pentagon, Washington, D.C., August 2, 2002

I have often been asked, at the end of a talk on climate change, if the problem couldn’t be solved by shrinking the size of the US military—which, questioners will sometimes assert, is the world’s “number one carbon emitter.” A comprehensive new report from the Watson Institute for International and Public Affairs at Brown University, “Pentagon Fuel Use, Climate Change, and the Costs of War,” authored by Neta Crawford, a professor of political science at Boston University, helps provide an answer to that question, or rather a series of answers. What they add up to is the idea that the Pentagon can play an outsized part in the climate fight—but only in part by cutting the amount of energy it uses. 

The Pentagon does indeed use a lot of energy. Maintaining an enormous military machine produces about 59 million metric tons of greenhouse gas emissions annually, which is more than most of the nations of the world—roughly the equivalent of a Denmark or a Sweden, two Bosnias, or five Cambodias. That’s because you mostly fight war by pouring gas into the tanks of… tanks. And airplanes, and ships, and trucks. As one might guess, fuel efficiency has not always been the highest concern of military planners—the sixty thousand Humvees still in the federal fleet average between four and eight miles to the gallon. For anything larger or more lethal, fuel is measured in gallons per mile. And, of course, the military operates a vast network of bases across the planet, all of which use power. 

Still—and this is very helpful in understanding the full dimension of our energy dilemma—this is not a particularly large share of the world’s, or even our nation’s, energy consumption. Crawford’s careful analysis shows that the Department of Defense consumes roughly a hundred million barrels of oil a year. The world runs through about a hundred million barrels of oil a day. Even though it’s the world’s largest institutional user of energy, the US military accounts, by Crawford’s figures, for barely 1 percent of America’s greenhouse gas emissions. A useful chart in one of the report’s appendixes shows that the military has, through all the peacetime and wars since 1975, produced fewer greenhouse gas emissions than the US as a whole produces in a single year. This number naturally goes up if you count the emissions from civilian military production, but in relative terms it remains counterintuitively small. 

All of this is valuable information to anyone trying to grasp the scale of the global warming problem. As giant a consumer as the Pentagon is, its use of energy pales next to that of the civilian population of some three-hundred million Americans—let alone that of a couple of billion humans wealthy enough to consume lots of fossil fuel. Imagine the vast stream of cars that enters and leaves any American city each rush hour and then multiply that by every day of the year. Picture the server farms required to stream every evening’s crop of Netflix shows, or the pulse of natural gas required to heat homes, or the mountains of coal needed to turn on the lights every evening in every home. Energy use is the result of a billion actions every minute of every day. 

Meanwhile, the military has actually been doing a not-too-shabby job of driving down its emissions—they’ve dropped 50 percent or so since 1991. In part, this is because the huge waste caused by earlier infrastructure has gradually declined across the economy—LED lights, for instance, make everyone more efficient. In part, too, the military has particular reasons to take efficiency seriously. Crawford quotes the then Marine Corps general (and later Trump chew toy) James Mattis from congressional testimony in 2011:

On the fuel, it is a significant Achilles heel for us when you have to haul the amounts of fuel that we have to haul around the battlefield for the generators and for the vehicles. We are working with DARPA [Defense Advanced Research Projects Agency], we are working with a number of civilian organizations to try and find solutions. There are efforts under way to make more expeditionary bases which would actually generate some of their own energy requirements using, for example, solar power. In many of these places, there is a lot of sunshine. If we can get expeditionary capability to capture that and then basically recharge our batteries. I mean, it is an amazingly complex effort to maintain the fuel lines. And it also gives the enemy an ability to choose the time and place of attacking us.

In other words, solar panels would shorten supply lines, a goal of every army in history. Crawford is right, I think, to insist that reducing the carbon footprint of the US military would reduce the global warming threat, but also right not to claim that it would have any kind of decisive effect. Denmark, after all, could go dark tomorrow without materially altering the climate change outcome for the planet.


But the military’s focus on energy use is uniquely important for other reasons, some of which Crawford explores. One is that, since Congress and presidents afford it incredible spending largesse (by some measures the US spends more on defense than the next seven countries combined), it has the freedom to explore new technologies that end up transferring to civilian use. Radar produced microwave ovens; the need for easy communications gave us, at some remove, the Internet. And so on. This ability could be harnessed more directly to help us build the new technologies and connect them in the systems necessary for a renewable energy age. The military-industrial complex may not be the single best place to conduct R&D, but given current political realities, it is likely to be one of the few places where it’s actually possible. 

Beyond that, the military spends much of its time engaged in the exercise that the rest of American public and private life seems to strenuously avoid: thinking hard about the future, with an emphasis on what could go wrong. This realism about risk and threats already led, over several decades, to regular Pentagon reports that defied Washington’s official nonchalance about climate change. As the climate expert Peter Gleick noted in a recent study:

It is vital to understand the history of U.S. intelligence and military assessments of the security implications of climate change. These assessments go back nearly four decades to the 1980s and since that time, hundreds of assessments of climate change, a massively growing body of literature on the impacts of human-caused climate change, and analyses from every U.S. defense, intelligence, and security agency have acknowledged the links between climate and security.

From the first of these reports three decades ago, the military has tended to be direct in delivering bad news. As Naval War College experts told the Senate in 1990, “naval operations in the coming half century may be drastically affected by the impact of global climate change. For the Navy to be fully prepared for operations in this future climate environment, resources of both mind and money must be committed to the problem.” That commitment most recently produced a DoD report to Congress released in January that began, “the effects of a changing climate are a national security issue with potential impacts to Department of Defense (DoD or the Department) missions, operational plans, and installations.” Considering the general tenor of the Trump administration toward climate reality, this is a strong statement, but many noted that the DoD seemed to be pulling at least some punches in deference to the current administration. A congressional request for a list of bases likely to be affected by climate change went largely unanswered, for instance, and Democratic congressman and House Armed Services Committee chairman Adam Smith said: “The Department of Defense presented no specifics on what is required to ensure operational viability and mission resiliency, and failed to estimate the future costs associated with ensuring these installations remain viable.” 

John Greim/LightRocket via Getty Images

Marine Corps Humvees, Marine Corps Base Camp Lejeune, North Carolina, February 2016

If this reticence continues it will be a sadly missed opportunity, because the Pentagon, when it speaks frankly, has the potential to reach Americans who won’t listen to scientists. In 2013, for example, Admiral Samuel Locklear, the commander of Pacific forces, told reporters that climate change “is probably the most likely thing that is going to happen… that will cripple the security environment, probably more likely than the other scenarios we all often talk about.… People are surprised sometimes,” he added. “You have the real potential here in the not-too-distant future of nations displaced by rising sea level.” Indeed. For if the UN estimate of two hundred million to a billion climate refugees by the end of this century is anything close to correct, that poses the greatest threat imaginable to peace on the planet. Only consider how thoroughly a million migrants from the Syrian crisis discombobulated Western politics in this decade. 

The most hopeful thought, of course, is that a move by the Pentagon—and the broader society it might influence—to more sustainable energy supplies could not only reduce the risk of all-out climate chaos, but it could also remove the most persistent justification for an outsized US military: the protection of oil supplies in the Middle East. At a moment when the White House is on a hair-trigger over suspicions that Iran has been attacking oil tankers, the prospect of how much tensions would be reduced on a planet that ran on widely available sun and wind is more attractive than ever. Crawford writes, “as a consequence of spending less money on fuel and operations to provide secure access to petroleum, the US could, in the long run, decrease US military spending and reorient its economy to more economically productive activities.” It could also free us to spend fewer anxious nights worrying about the next war and the next heatwave.


New York Review + Paris Review covers

Save $168 on an inspired pairing!

Get both The New York Review and The Paris Review at one low price.

Already a subscriber? Sign in