Out Of All Greenhouse Gas Emitters On Earth, One US Organization Takes The Biscuit

The US Department of Defense has acknowledged that climate change is one of the biggest threats to global security currently facing the world. In a twist of irony, the biggest producer of greenhouse gas emissions of any institution on Earth is, uh, their military.

Between 2010 to 2019, the US armed forces pumped out 636 million metric tons of CO₂. Though annual emissions declined from roughly 76 million metric tons in 2010 to about 55 million by the end of the decade, the American armed forces still generate more CO₂ than most countries.

This massive carbon footprint is the byproduct of a sprawling global operation. All in all, the US has 900 domestic bases and installations, as well as nearly 800 international bases and smaller military installations dotted around the world. 

Bear in mind that the US isn’t the biggest military by number of soldiers. Both China and India, two countries with populations over 1 billion, have more soldiers, but the US spends significantly more on its military and appears to require more energy to maintain itself. 

From powering far-flung bases to fueling fleets of aircraft, ships, and land vehicles, the US military's day-to-day operations require constant training exercises, weapons testing, and the vast logistical effort of moving personnel and equipment across continents. Even in times of relative peace, unbelievable amounts of energy are needed to keep the machine ticking. 

In a new study, researchers explore ways in which the energy consumption of the US military could be reduced. 

Chief among the findings, their work showed that reductions in military spending were tightly associated with decreased energy consumption. When budgets were cut, there were significant reductions in energy consumption from facilities, vehicles, and equipment, and – most notably – jet fuel. 

The research comes at a time when the world is splurging unprecedented amounts of money on the military. In 2024, world military expenditure rose by 9.4 percent from the previous year, marking the steepest annual rise since the end of the Cold War. The US was no exception, boosting its defense budget by 5.7 percent to a staggering $997 billion.

Ironically, this increased spending will result in more greenhouse gas emissions, contributing to rising global temperatures – an outcome that the US Department of Defense believes will fuel greater global instability and, ultimately, spark more conflicts.

However, it would be naively optimistic to assume the US military is going to slash its funding to cut climate-warming emissions. The global system is immensely complex, and climate change won’t be solved by cutting a few military budgets (don’t forget the biggest carbon emitters are energy production, agriculture, transportation, and manufacturing). 

Nevertheless, as the world warms, ignoring the defense sector's energy footprint not only undermines climate efforts but also reinforces a dangerous paradox: attempting to secure the future of a planet that is becoming increasingly uninhabitable. If global security is truly the goal, then sustainability must become part of the mission.

The study is published in the journal PLOS Climate.