During the November 15 Democratic Presidential Debate, Vermont Senator Bernie Sanders sounded an alarm that "climate change is directly related to the growth of terrorism." Citing a CIA study, Sanders warned that countries around the world are "going to be struggling over limited amounts of water, limited amounts of land to grow their crops and you're going to see all kinds of international conflict."

On November 8, the World Bank predicted that climate change is on track to drive 100 million people into poverty by 2030. And, in March, a National Geographic study linked climate change to the conflict in Syria: "A severe drought, worsened by a warming climate, drove Syrian farmers to abandon their crops and flock to cities, helping trigger a civil war that has killed hundreds of thousands of people."

The sobering insight that climate change can accelerate violence should weigh heavily on the minds of delegates to the United Nations Framework Convention on Climate Change in Paris—a city that, on November 13, suffered grievously from the blowback of the Syrian conflict. But there is another looming threat that needs to be addressed.

Put simply: War and militarism also fuel climate change.

From November 30 to December 11, delegates from more than 190 nations will convene in Paris to address the increasingly visible threats of climate disruption. The 21st Conference of the Parties (aka COP21) is expected to draw 25,000 official delegates intent on crafting a legally binding pact to keep global warming below 2°C.

But it is difficult to imagine the delegates reaching this goal when one of the largest contributors to global-warming has no intention of agreeing to reduce its pollution. The problem in this case is neither China nor the United States. Instead, the culprit is the Pentagon.

The Pentagon's Carbon Bootprint

The Pentagon occupies 6,000 bases in the US and more than 1,000 bases (the exact number is disputed) in 60-plus foreign countries. According to its FY 2010 Base Structure Report, the Pentagon's global empire includes more than 539,000 facilities at 5,000 sites covering more than 28 million acres.

The Pentagon has admitted to burning 350,000 barrels of oil a day (only 35 countries in the world consume more) but that doesn't include oil burned by contractors and weapons suppliers. It does, however, include providing fuel for more than 28,000 armored vehicles, thousands of helicopters, hundreds of jet fighters and bombers and vast fleets of Navy vessels. The Air Force accounts for about half of the Pentagon’s operational energy consumption, followed by the Navy (33%) and Army (15%). In 2012, oil accounted for nearly 80% of the Pentagon's energy consumption, followed by electricity, natural gas and coal.

Ironically, most of the Pentagon's oil is consumed in operations directed at protecting America's access to foreign oil and maritime shipping lanes. In short, the consumption of oil relies on consuming more oil. This is not a sustainable energy model.

The amount of oil burned—and the burden of smoke released—increases whenever the Pentagon goes to war. (Indeed, human history's most combustible mix may well prove to be oil and testosterone.) Oil Change International estimates the Pentagon's 2003-2007 $2 trillion Iraq War generated more than three million metric tons of CO2 pollution per month.

The Pentagon: A Privileged Polluter

Yet, despite being the planet's single greatest institutional consumer of fossil fuels, the Pentagon has been granted a unique exemption from reducing—or even reporting—its pollution. The US won this prize during the 1998 Kyoto Protocol negotiations (COP4) after the Pentagon insisted on a "national security provision" that would place its operations beyond global scrutiny or control. As Undersecretary of State Stuart Eizenstat recalled: "Every requirement the Defense Department and uniformed military who were at Kyoto by my side said they wanted, they got." (Also exempted from pollution regulation: all Pentagon weapons testing, military exercises, NATO operations and "peacekeeping" missions.)

After winning this concession, however, the US Senate refused to ratify the Kyoto Accord, the House amended the Pentagon budget to ban any "restriction of armed forces under the Kyoto Protocol," and George W. Bush rejected the entire climate treaty because it "would cause serious harm to the US economy" (by which he clearly meant the U.S. oil and gas industries).

Today, the Pentagon consumes one percent of all the country's oil and around 80 percent of all the oil burned by federal government. President Barack Obama recently received praise for his Executive Order requiring federal agencies to cut greenhouse gas emissions by 2020, but Obama's EO specifically exempted the Pentagon from having to report its contribution to climate chaos. (As a practical matter, the Pentagon has been forced to act. With battlefield gas costing $400 a gallon and naval bases at risk of flooding from rising seas, the Pentagon managed to trim its domestic greenhouse-gas emissions by 9 percent between 2008-2012 and hopes to achieve a 34 percent reduction by 2020.)

Climate Chaos: Deception and Denial

According to recent exposés, Exxon executives knew the company's products were stoking global temperatures but they opted to put "profits before planet" and conspired to secretly finance three decades of deception. Similarly, the Pentagon has been well aware that its operations were wrecking our planetary habitat. In 2014, Pentagon chief Chuck Hagel identified climate change as a "threat multiplier" that will endanger national security by increasing "global instability, hunger, poverty, and conflict." As far back as 2001, Pentagon strategists have been preparing to capitalize on the problem by planning for "ice-free" operations in the Arctic—in anticipation of US-Russian conflicts over access to polar oil.

In 2014, Tom Ridge, George W. Bush's Homeland Security chief, stated flat-out that climate change posed "a real serious problem" that "would bring destruction and economic damage." But climate deniers in Congress continue to prevail. Ignoring Ridge's warnings, a majority of House Republicans hammered an amendment onto the National Defense Authorization bill that banned the Pentagon from spending any funds on researching climate change or sustainable development. "The climate . . . has always been changing," Rep. David McKinley (R-W.Va) said dismissively. "[W]hy should Congress divert funds from the mission of our military and national security to support a political ideology?"

Since 1980, the US has experienced 178 "billion dollar" weather events that have caused more than $1 trillion in damages. In 2014 alone, there were eight "billion dollar" weather calamities.

In September 2015, the World Health Organization warned climate change would claim 250 million lives between 2030 and 2050 at a cost of $2-4 billion a year and a study in Nature Climate Change estimated the economic damage from greenhouse emissions could top $326 trillion. (If the global warming causes the permafrost to melt and release its trapped carbon dioxide and methane gases, the economic damage could exceed $492 trillion.)

In October 2015 (the hottest October in recorded weather history), BloombergBusiness expressed alarm over a joint study by scientists at Stanford and the University of California at Berkeley that predicted global warning "could cause 10 times as much damage to the global economy as previously estimated, slashing output as much as 23 percent by the end of the century."

This is more than a matter of "political ideology."

The Pentagon's role in weather disruption needs to become part of the climate discussion. Oil barrels and gun barrels both pose a threat to our survival. If we hope to stabilize our climate, we will need to start spending less money on war.