Trump’s huge spending boost for the Pentagon will produce an additional 26 megatons (Mt) of planet-heating gases – on a par with the entire annual carbon equivalent (CO2e) emissions generated by 68 gas power plants or the entire country of Croatia, new research reveals.
The Pentagon’s 2026 budget – and climate footprint – is set to surge to $1tn thanks to Trump’s One Big Beautiful Act, a 17% rise on last year.
Military emissions are closely tied to military spending.
The budget bonanza will push the Pentagon’s total greenhouse emissions to a staggering 178 Mt of CO2e, resulting in an estimated $47bn in economic damages globally, according to new analysis by the Climate and Community Institute (CCI), a US-based research thinktank, shared exclusively with the Guardian.
The huge increase in military spending comes amid worsening climate breakdown, and as Americans – many of them Trump voters – are being hit by destructive extreme weather events such as wildfires, extreme heat and the recent floods in Texas, as well as sea-level rise and other slow-onset climate effects.
Trump’s 2026 budget legislation slashes federal funding for science, education, Medicaid, food stamps, emergency management, the National Weather Service and humanitarian aid – in order to pay for the military expansion, tax cuts for the wealthy, and Trump’s violent immigration crackdown. Trump has also withdrawn the US from the Paris climate accords for the second time, and rolled back Biden-era investments in renewable energies such as solar and wind that are key to weaning the US off fossil fuels in order to curtail climate catastrophe.
The US is the largest historical contributor to the climate crisis, and currently the second worst emitter after China – a country with quadruple the population.
Emitting 178 Mt of CO2e would make the US military and its industrial apparatus the 38th largest emitter in the world if it were its own nation – and more than the entire annual carbon footprint of Ethiopia, a country of 135 million people.
“Every extra dollar grows the Pentagon’s carbon bootprint – and shrinks the chances for a livable future. With this additional funding from the big beautiful bill, the US’s trillion-dollar war machine will be responsible for more emissions than 138 individual countries,” said Patrick Bigger, lead author and CCI research director.
“Supposedly this spending is for national security. But what security is there in more droughts, floods, hurricanes, and rising seas?”
“Every dollar of military spending has a climate cost, with procurement decisions being made now risking locking us into decades of emissions through carbon-intensive military equipment,” said Ellie Kinney, climate advocacy coordinator at the Conflict and Environment Observatory (Ceobs).
The Pentagon – the US armed forces and Department of Defense (DoD) agencies – is the largest single fossil-fuel consumer in the US, already accounting for about 80% of all government emissions. In 2023, it spent $860bn, generating almost 152Mt of climate pollution through a combination of overseas operations, jet-fuel consumption and domestic base upkeep – as well as emissions from manufacturing the weapons, ships, tanks and planes it operates, according to a previous analysis by Transnational Institute.
The 2026 emissions figure uses the same methodology based on military spending, calculating emissions from the Pentagon’s operations and full supply chain from the vast US military-industrial complex.
The US currently operates 877 overseas military bases – two and a half times more than the rest of the world combined, according to recent analysis. A growing share of the Pentagon budget goes to private companies, with more than half its discretionary spending between 2020 and 2024 going to weapons contractors.
The Pentagon has long been the world’s largest institutional greenhouse gas emitter. The 2026 $1tn budget will make the total Pentagon carbon footprint equivalent to the annual emissions from 47 coal power plants.
Yet the Pentagon’s true climate impact will almost certainly be worse, as the calculation does not include emissions generated from future supplemental funding such as the billions of dollars appropriated separately for military equipment for Israel and Ukraine in recent years.
Every megaton of CO2 counts, as emissions drive global heating, which is supercharging deadly, destructive and costly extreme weather such as hurricanes, wildfires and drought.
The US is already spending nearly $1tn a year on disaster recovery, one recent analysis found. Next year’s Pentagon emissions will cause $47bn in economic damages including impacts on agriculture, human health and property from extreme weather, according to the EPA social cost of carbon calculator, adjusted to 2025 dollars.
The $150bn Pentagon budget top-up is about five times the annual budget allocated to the Federal Emergency Management Agency (Fema) in recent years – an agency that Trump has threatened to eliminate entirely.
“Amidst a summer of oppressive heat, the Trump administration is dismantling the government’s disaster preparedness and response capabilities. Prioritizing military expansion while underfunding disaster response doesn’t keep communities safe,” said co-author Lorah Steichen, policy manager at CCI.
“The $150bn increase to military spending is comparable to the amount needed to fund whole-building, deep-energy retrofits for all the nation’s public housing units – a true investment in human security.”
US military spending and emissions are the highest in the world by a long way. And it is thanks to the US that states are not required to account for military emissions to the UN. In the run-up to the Kyoto protocol, the 1997 international treaty that set binding targets for greenhouse gas reductions, the Pentagon successfully lobbied the Clinton White House to push for a blanket exemption for emissions generated by military fuel use.
Still, the total military carbon footprint is estimated at about 5.5% of global emissions – excluding greenhouse gases from conflict and war fighting. This is more than the combined contribution of civilian aviation (2%) and shipping (3%).
And the Pentagon has long warned that water scarcity, sea-level rise and desertification in vulnerable regions could lead to political instability and forced migration, framing climate change as a “threat multiplier” to US interests. In 1991, George HW Bush formally acknowledged climate change as a national security threat.
In March this year Trump’s defence secretary, Pete Hegseth, wrote on X: “The @DeptofDefense does not do climate change crap. We do training and warfighting.”
Hegseth ordered the termination of dozens of climate studies and renewable energy programs at the Pentagon aimed at making the military both more efficient and resilient.
The Pentagon did not respond to requests for comment. The 2024 report is no longer on its website.
Military spending is rising across the globe, hitting a record $2.7tn in 2024. This military buildup will have catastrophic climate consequences.
Kinney from Ceobs said: “We cannot keep ignoring the military’s contribution to the climate crisis – militaries must be transparent about the scale of their emissions and must make serious commitments to reduce their carbon footprint.”
