Iran war has already released a staggering amount of CO2 — and the destruction of schools, homes and buildings is the biggest source

The first two weeks of the war between the U.S., Israel and Iran created immense present and future greenhouse gas emissions, draining the global carbon budget faster than 84 countries combined, a new analysis finds.

Between Feb. 28 and March 14, 2026, the warring parties released almost 5.6 million tons (5.1 million metric tons) of carbon dioxide (CO₂) and other greenhouse gases by firing carbon-intensive weapons, powering fighter jets and ships, and bombing infrastructure such as oil storage facilities and civilian buildings, researchers found.

For comparison, if these emissions continued at the same rate for one year, they would be roughly equivalent to the annual carbon emissions of the 84 lowest emitting countries in the world combined. And the emissions from the first two weeks of the conflict are higher than Iceland's annual carbon emissions, which in 2024 totaled 4.7 million tons (4.3 million metric tons) of CO₂ via all sources, the team said.

"Every missile strike is another downpayment on a hotter, more unstable planet, and none of it makes anyone safer," Patrick Bigger, a co-author of the analysis and a research director at the Climate and Community Institute, a climate and economy think tank, told The Guardian.

The analysis and an accompanying opinion article written by the researchers were published March 21 by the Climate and Community Institute.

The biggest source of CO₂ from the conflict in Iran during its first two weeks was the destruction of homes, schools and other buildings, as the rubble will need to be cleared and the infrastructure must be rebuilt after the war ends, according to the analysis. Bigger and his colleagues calculated that these indirect emissions amount to about 2.7 million tons (2.4 million metric tons) of CO₂, which is equivalent to the Maldives' yearly emissions. Based on data from Red Crescent Society of Iran, a humanitarian organization, the infrastructure that has been razed includes 16,191 residential buildings, 3,384 commercial units, 77 medical centers and 69 schools, the researchers noted in the study.

The second largest chunk of CO₂ emissions from the first 14 days of the war came from the U.S., Israel and Iran's bombarding of oil storage facilities, oil refineries and oil tankers across the Gulf region. The researchers found that 2.5 million to 5.9 million barrels of oil were blown up during their analysis period, unleashing 2.1 million tons (1.9 million metric tons) of CO₂ and other greenhouse gases into the atmosphere — roughly equivalent to Malta's annual emissions.

Fuel used during combat and support operations in the first two weeks of the war was the third-biggest source of CO₂, totaling about 583,000 tons (529,000 metric tons) of the greenhouse gas, which is comparable to Greenland's yearly emissions. The U.S. and Israel struck more than 6,000 targets in Iran using fighter jets and bombers between Feb. 28 and March 14, according to the analysis. This is equivalent to about 2,500 flights lasting three hours each, which, together with the transport of troops and other support activities, likely consumed 150 million to 270 million liters (40 million to 71 million gallons) of fuel, the researchers estimated.

In the first two weeks of the war, the U.S. lost three F-15 fighter jets and one KC-135 refueling aircraft. In the same period, Iran is reported to have lost 28 planes, 21 ships and about 300 missile launchers. This equipment will likely be replaced through manufacturing, and this makes up the fourth-largest source of CO₂ in the analysis, totaling 190,000 tons (172,000 metric tons) of the greenhouse gas. That's about the same as Tonga's annual emissions.

Finally, the researchers estimated that the U.S. and Israel launched 9,000 missiles in the first 14 days of the war. Iran, meanwhile, is thought to have launched 1,000 missiles and about 2,000 drones in the same period. Similar to planes, ships and missile launchers, the warring parties will likely replenish this arsenal, which also includes interceptor missiles. According to the analysis, the embodied CO₂ emissions amount to roughly 61,000 tons (55,000 metric tons), which is equivalent to a small cement plant's yearly emissions.

The war is in its fourth week, meaning that far more CO₂ has now been emitted directly and indirectly as a result of the conflict than the analysis suggests.

"We expect emissions to increase rapidly as the conflict proceeds, mainly due to the speed [at] which oil facilities are being targeted at an alarming rate," Fred Otu-Larbi, a co-author of the analysis and a researcher at Lancaster University in the U.K. and the University of Energy and Natural Resources in Ghana, told The Guardian. "Just what are the costs, no one really knows, that is why studies like this are so vital."

If more countries join the war, they could significantly boost emissions, the researchers wrote in the analysis. But already, "burning up the annual emissions of Iceland in two weeks is something we really cannot afford," Otu-Larbi said.

The aftershocks of the war are expected to have an even bigger climate impact than the fighting itself, as countries seek to buffer against fuel and fertilizer shocks caused by Iran's blockade of the Strait of Hormuz. Specifically, there could be an increase in drilling for fossil fuels as countries seek to become as energy secure as possible, the researchers said.

"Historically, every U.S.-driven energy shock has been followed by a surge in new drilling, new LNG [liquified natural gas] terminals and new fossil-fuel infrastructure," Bigger said. "This war risks hard-wiring another generation of carbon dependence."