How has the Iran war geopolitical conflict affected how much carbon dioxide is being added to the Earth's air?
Thanks to its unique timing, atmospheric carbon dioxide concentration data collected by the remote Mauna Loa Observatory may provide a unique, almost real-time window into how a large-scale military and economic conflict can affect the environment.
What makes the timing unique is the conflict's major military actions began on 28 February 2026. That gives us the potential of a clear break in the monthly atmospheric CO₂ data, with a well defined before and after.
What makes that possible is the disruption of oil and gas shipments from the energy resource-rich nations of the region, which before the conflict, accounted for about 20% of the world's oil supply. The bulk of these oil shipments are bound for the nations of south and east Asia. Or would be, if the oil tankers carrying the supply were not at high risk of being attacked by Iranian drones, while Iran's own oil shipments are blocked by a naval blockade.
That much oil and gas powers a large share of the advanced economies that rely on the supply from this region. If those shipments stop, that's a lot of economic activity that can be shut down unless the supplies can be offset through strategic reserves or alternate sources. That reduced activity would reduce the net amount of CO₂ these economies emit into the Earth's atmosphere.
This assumes any fires resulting from military actions or from the increased flaring of excess gas production that cannot be captured and shipped to other countries because of the geopolitical event's disruption of shipping produce substantially less CO₂ emissions than these more productive activities.
With these assumptions, what we would look for in the data for the months after February 2026 is a reduction in the rate at which carbon dioxide accumulates in the Earth's atmosphere. Given the time it takes for carbon dioxide emissions to diffuse into the air from the affected economies and reach the remote Mauna Loa Observatory where it is measured, that reduction should start very slowly before falling off more sharply as the disruption continues.
At least that's our working hypothesis. Since the NOAA just got around to publishing the monthly CO₂ data measured at the Mauna Loa Observatory for both March and April 2026 last week, we can look to see how much of an effect there may be already in the two months since the conflict began. The following chart shows the data for the trailing year average of the year-over-year change in atmospheric CO₂ concentration from January 2000 through April 2026:
What we see is that since December 2024, the rate at which carbon dioxide is being added to the Earth's air has been falling, with the rate affected by developments in global trade.
At least, up through February 2026, which has been generally falling at a steady rate. After February 2026, there are indications the pace at which CO₂ is emitted into the atmosphere has started declining at a faster pace. But that's based on a sample size of two months. We'll need more months of data to sort out the Iran war's impact, but at these early days, it appears to be following our hypothesis.
When we get that data and compare it against where the established trend for the data, we'll be able to put a dollar value on its impact to the world's GDP and compare it with other geopolitical events.
References
National Oceanographic and Atmospheric Administration. Earth System Research Laboratory. Mauna Loa Observatory CO2 Data. [Online Data]. 5 May 2026. Accessed 8 May 2026.
Image credit: Tankers at the Iraqi Al Basra Oil Terminal in the Northern Arabian Gulf photo by Samuel W. Shavers on Wikimedia Commons. Public domain image.