The Carbon Cost of War — How Gaza, Ukraine, and Iran Are Cooking the Climate While the UN Looks Away

When delegates gathered for COP30 in Belém last November, they scrutinized aviation, agriculture, steel, cement — every sector of the global economy that releases carbon. One topic was conspicuously absent from the formal agenda: war. Not because the emissions are small. Because the rules say countries don't have to report them. The U.S., China, and Russia — the three largest military spenders on Earth — submit either no military emissions data at all or numbers so aggregated that the carbon footprint of their armed forces is impossible to extract. Militaries are estimated to be responsible for about 5.5% of global greenhouse gas emissions. That is more than aviation. More than shipping. And it is, by international design, invisible.

What follows is a stocktake of three wars currently burning through the planet's remaining carbon budget — Ukraine, Gaza, and Iran — translated, where the abstract tonnage starts to lose meaning, into something a person can actually picture. A flight. A coal plant. A country.

Ukraine: 311 million tonnes, four years in

The composition of Ukraine's war emissions is the part that matters for understanding how war damages the climate even after the shooting stops. Direct combat — fuel for tanks and jets, ammunition production, fortification construction — accounts for about a third of the total. The rest comes from what war does to everything around it: landscape fires that surged when summers got hotter and battlefields drier, attacks on power infrastructure that forced Ukrainian cities onto carbon-intensive backup generators all winter, civilian aviation rerouted around closed airspace burning extra fuel for years on end, and — accounting for the largest single share — the future emissions locked in by reconstruction. Every destroyed apartment block has to be rebuilt. Concrete and steel are among the most carbon-intensive materials humans manufacture. Bombing a city is, in carbon terms, a bet that the city will be rebuilt — and the climate pays the bet whether the war ends in victory, defeat, or stalemate.

Ukraine's planned action at COP31 is the first attempt to convert this accounting into legal accountability: filing a claim under the Environmental Damage category of the Register for Ukraine, demanding more than €37 billion from Russia in what would be the world's first case of climate reparations from war. At a social cost of $185 per tonne of CO₂, the numbers add up. Whether any international mechanism exists to actually collect them is a different question.

Gaza: 33 million tonnes, with reconstruction not yet begun

That last ratio — twenty-four to one — is the part of war-emissions accounting that climate journalism still struggles to convey. To destroy a city is, in pure tonnage, a relatively small carbon event: jets and rockets and tanks burn a lot of fuel, but only over a finite period and in finite quantities. To rebuild a city — to manufacture all the steel and pour all the concrete and fire all the kilns required to put 450,000 apartments back where they used to stand — is a carbon expenditure that lasts for decades and dwarfs the war that necessitated it. Every collapsed building in Gaza is a carbon promissory note: the destruction was a down payment, and the climate will collect on the principal.

And those numbers do not yet include what destroyed water and sanitation systems are doing in real time. The Norwegian Refugee Council reported that 130,000 cubic meters of untreated sewage are being discharged into the Mediterranean every day. Six of Gaza's eight wastewater treatment plants are damaged or destroyed. Seventy-three of 84 sewage pumping stations are gone. None of that appears in the carbon accounting, because methane and water-borne emissions aren't easily measurable in a war zone — but they are happening, every day, while the world looks at the death toll and looks away from everything else.

Iran: the war that just keeps burning oil

The Iran war's carbon problem is structurally different from Gaza's or Ukraine's: it is a war fought largely through, and against, the world's oil infrastructure. Israeli strikes have hit fuel depots, refineries, and storage facilities. Iranian retaliation has hit Gulf oil infrastructure including a fire at the UAE's Fujairah oil facility this past weekend. Every burning oil tank is, simultaneously, a tactical objective and a several-thousand-tonne carbon release. As of June 2025, climate scientists estimated the remaining global carbon budget for staying below 1.5°C of warming at 130 billion tonnes of CO₂e. Current human emissions are roughly 40 billion tonnes per year. The budget runs out in 2028 if nothing changes. A war that burns Iceland's annual emissions in two weeks is not, on a long enough timeline, a regional event. It is a global one.

And the war is reshaping the energy economy in ways that will outlast the fighting by decades. Analysts at the Center on Global Energy Policy and the Natural World Fund have both noted the same pattern: every US-driven energy shock since the 1970s has been followed by a surge in new drilling, new LNG terminals, and new fossil-fuel infrastructure investment. The Iran war has already revived plans for the IMEC corridor (an India-to-Israel-to-Europe pipeline route bypassing Hormuz), pushed Saudi Arabia to consider expanding its East-West pipeline, and sent Latin American LNG projects scrambling to fill the supply gap. The decarbonization timeline does not survive a regional war fought on oil terrain. The war is, among other things, hard-wiring another generation of carbon dependence into the global energy system.

The blind spot built into the Paris Agreement

None of these emissions are required to be reported anywhere. The 1997 Kyoto Protocol explicitly exempted military activities from greenhouse gas accounting at the insistence of the United States. The 2015 Paris Agreement softened the language but kept the loophole structural: military emissions are reported only voluntarily, and aggregated into broader national figures in ways that make it impossible to extract them. The U.S. Department of Defense — the world's largest single institutional consumer of petroleum — does not publish a meaningful emissions inventory. Russia and China publish less. The IPCC's national reporting guidelines do not have a category for "war." The number of countries that file Annual Inventory Reports including a military line item is approximately zero.

This is not a technical oversight. It was negotiated. The same governments that turn up at COP every year promising 1.5°C alignment are the governments that built the exemption into the treaty so their militaries wouldn't have to count. What gets measured gets managed is a clichéd phrase from corporate consulting; it also happens to be true. What does not get measured does not get managed. War emissions do not get measured. War emissions do not get managed.

"Why bother recycling when…"

There is a generational consequence to all of this that polling has started to pick up clearly. Gen Z, who grew up being told their daily choices — recycling, reusable cups, vegetarian Mondays, careful flying — would matter for the climate, are watching governments emit more carbon in a single airstrike on an Iranian fuel depot than the entire population of a small city would save in a lifetime of conscientious recycling. The result is measurable in surveys. It is not apathy. It is something more specific, and more dangerous: futility.

Those numbers come from the GlobeScan/BBMG From Anxiety to Agency global survey of 30,216 people across 31 markets, the Ipsos Earth Day 2024 report, and a 2021 study of 10,000 young people across 10 countries. The trend is consistent across surveys, demographics, and continents: young people are not becoming climate deniers. They are becoming climate fatalists. The belief that the climate crisis is real has not weakened — it has intensified. What has weakened is the belief that anything they can personally do will alter the trajectory. The number who say their individual actions matter has dropped from two-thirds in 2019 to just over half today, per AP-NORC polling. The number who say corporations and governments are primarily responsible has risen sharply.

This shift, in fairness, is partly a correction. The "carbon footprint" framing — the entire individualized-responsibility mode of climate thinking — was originally a 2004 BP advertising campaign designed by Ogilvy & Mather, with the explicit strategic goal of moving moral attention away from oil companies and onto consumers. That a generation has finally caught on to the framing is, in one reading, a healthy political maturation. The 100 fossil-fuel companies that produce 70% of historical greenhouse gas emissions are not your kitchen recycling bin. Recognizing that is correct.

And the wars are accelerating this. When a young person opens their phone to see Israeli strikes setting fire to 5.9 million barrels of Iranian oil, or Russian artillery turning Ukrainian forests into a 1.39-million-hectare 2025 fire season, or Gaza's reconstruction quietly committing the climate to 24 times the emissions of the bombing that necessitated it — the message that "your choices matter" lands differently than it did in 2019. The arithmetic of individual action versus state-scale destruction has stopped being abstract. A New Yorker recycling pizza boxes for fifty years saves the carbon equivalent of about ten minutes of the Iran war's military fuel consumption. Gen Z has done the math, and the math is brutal.

What replaces the carbon-footprint frame matters enormously, and the polling suggests three patterns are emerging in parallel. The first is collective political action — youth climate activism, voting on climate, running for office. The Penn Center for Science, Sustainability, and the Media's research finds that "collective action can help alleviate climate anxiety" specifically for young people, where individual action no longer can. The second is targeted institutional pressure — divestment campaigns, climate litigation against fossil-fuel majors (over 2,500 cases now globally), shareholder activism, refusal to work for petroleum companies. The third — the worrying one — is opt-out: a quiet emotional disengagement from the entire frame, accompanied by the soft conclusion that since the planet is already cooked, you might as well order the cheap flight, eat the steak, and stop pretending. The wars are pulling people toward all three responses simultaneously.

The piece of climate communication this generation is still missing — and that newsrooms and climate organizations have largely failed to provide — is the bridge between accurate diagnosis (yes, your individual actions are dwarfed by Aramco and the Pentagon) and effective response (here is the specific lever that does scale). "Recycle your bottles" doesn't survive contact with a 600-mile-deep airstrike. "Vote, organize, sue, divest, refuse to work in fossil fuels, push your pension fund off oil" might. But the second message is harder to put on a poster, and the wars are happening faster than the messaging can be rewritten.

The unintended push: how the war is accelerating renewables

Here is the part of the story that most climate journalism has been slow to write — partly because it sits uncomfortably alongside the human cost, and partly because nuance does not headline well. The same fossil-fuel shock that is pumping carbon into the atmosphere through burning oil depots and reconstruction-bound steel is, simultaneously, doing something the climate movement has spent two decades trying to engineer: making renewables the obviously cheaper, safer, more strategic option for governments that import their energy. The Iran war, in particular, may end up being the moment a generation of Asian and African economies decides the era of fossil-fuel security is over.

The data on this is real and it is happening fast. Three months into the war, every measurable indicator of energy-transition velocity has accelerated:

This is the largest fossil-fuel demand shock since the 1973 OPEC embargo. The 1973 embargo gave the world the Toyota Corolla, Japanese fuel-economy regulations, the US Strategic Petroleum Reserve, and a generation of policy infrastructure that still shapes energy markets today. The 2022 Russian invasion of Ukraine gave Europe REPowerEU, a record acceleration of renewables, and the death of European energy reliance on Russian gas. The 2026 Iran war is, on early evidence, doing for Asia what Ukraine did for Europe. Pakistan was already importing cheap Chinese solar at scale before the war started, and has been substantially insulated from the price shock. Other Asian importers are watching that and drawing the obvious conclusion.

The behavioral changes are also real, and they are the kind that have a way of becoming permanent. The Philippines, Sri Lanka, and Pakistan have moved government offices to a four-day work week. Thailand and Vietnam are urging work-from-home. The Philippines is targeting a 20% reduction in government energy use. Experts at Durham University Business School and the Stanford Graduate School of Business note that millions of workers are about to spend an extended period proving they can get the job done in four days — and that this is exactly the kind of forced experiment that has historically pushed labor-policy norms to permanently shift. The post-COVID hybrid-work transition started exactly this way.

The medium-term math is, however, genuinely shifting. As IEA Director Fatih Birol put it: "Ten years ago, solar was a romantic story — but now solar is a business." Renewable power was already 85% of new global power capacity additions in 2025. The Iran war has not started this trend. It has accelerated a trend that was already structurally underway, and it has done so by demonstrating to every energy-importing country in Asia and Africa that fossil-fuel-based energy security is, in 2026, an oxymoron. Solar panels and battery storage do not stop working when an oil tanker is hit by a missile. Wind farms do not depend on a 39-kilometer-wide chokepoint patrolled by a hostile navy. Energy security and decarbonization, once treated as competing priorities, have started to look like the same thing.

What this means for the carbon-budget question above is genuinely complicated. The wars are still releasing more carbon, in the near term, than they will save in the medium term — the 24-to-1 reconstruction ratio in Gaza alone will dwarf any savings from accelerated solar adoption for years. But over a multi-decade horizon, the calculus changes. If the Iran war pushes Asia onto a permanently lower fossil-fuel trajectory the way Ukraine pushed Europe, the avoided emissions over twenty years could exceed the war's direct emissions by an order of magnitude. The world has been here before: every previous oil shock — 1973, 1979, 2022 — has been followed by a measurable, durable, structural decline in oil demand. The 2026 shock looks bigger than any of those, and is hitting at a moment when the alternatives are cheaper than they have ever been.

That does not absolve anyone of anything. The bombs falling on Tehran are not falling there to advance the energy transition. The reconstruction emissions in Gaza are not a price worth paying for cheaper Vietnamese solar. But it is true, and important, that history has a way of refusing to assign credit cleanly. The most consequential decarbonization push of the 21st century may end up having been, in part, the unintended consequence of three wars that no one wanted and no one started for the climate. The world will sort the moral books later. The carbon budget runs out on its own schedule.

The bigger picture

The framing in most climate journalism treats war and climate as separate problems. They are not. They are the same problem viewed from two different angles. Every war that burns through the carbon budget pulls a 1.5°C world out of reach for every climate-vulnerable country that didn't start any of these wars and won't be allowed to opt out of any of their consequences. The Maldives does not get to "abstain" from the warming generated by Ukrainian fires, Gazan reconstruction, or Iranian oil depot bombings. Bangladesh does not get to negotiate down its share of the resulting sea-level rise. The carbon doesn't care about the politics. It just stays in the atmosphere for the next century, doing what carbon does.

And the structural silence on this is — like most things in climate policy — load-bearing. If militaries had to count, militaries would have to act. If wars were costed in carbon as well as in dollars and lives, the tradeoffs would look different. If a US carrier strike group's emissions appeared in a federal climate inventory, the conversation about whether the next conflict was worth fighting would include a column it currently does not. The exemption is not an accounting accident. It is a policy choice. Like every policy choice, it can be unmade.

Ukraine's planned reparations claim is one front. The Initiative on GHG Accounting of War's open methodology is another — anyone can use it, including civil society groups and journalists, to attribute emissions to the actors who caused them. The Center for Environmental Initiatives Ecoaction, the Conflict and Environment Observatory (CEOBS), PAX, and Brown's Costs of War project are all building parallel datasets that can be cited in courts, in COP submissions, and in journalism. The blackout is not because the data doesn't exist. It is because almost no one with editorial authority over front pages has decided to make it the story. The carbon from these three wars will outlive every government currently fighting them. Whether anyone is held responsible for it is up to the people insisting it be counted.