Carbon Accounting Can Help Tackle the Hidden Emissions of War

Why It Matters

The hidden climate cost of war inflates global emissions and undermines climate targets, while transparent accounting could steer reconstruction funds toward low‑carbon infrastructure. Ignoring these emissions perpetuates a policy blind spot that hampers accountability and climate finance effectiveness.

Key Takeaways

• Iran war emitted over 5 million tonnes CO₂e in two weeks
• First six days US spending $11.3 bn produced ~3.4 Mt CO₂e
• Reconstruction could add emissions exceeding combat, via cement, steel
• No consistent war emissions reporting in Paris Agreement or Kyoto
• Embedding carbon accounting in reconstruction finance aligns with climate commitments

Pulse Analysis

The environmental footprint of modern warfare is often invisible, yet recent analysis of the US‑Israeli operation against Iran reveals a staggering climate impact. By applying UK government greenhouse‑gas accounting rules to publicly disclosed spending, analysts calculated that the first two weeks of hostilities released over 5 million tonnes of CO₂e, comparable to the annual emissions of a small European nation. The same spend‑based model shows that the $11.3 billion the United States poured into the conflict during its opening six days generated roughly 3.4 million tonnes of CO₂e, underscoring how military logistics translate directly into greenhouse‑gas output.

Beyond the battlefield, the reconstruction phase threatens to eclipse combat emissions. Historical data indicate that every $1 billion allocated to rebuilding infrastructure—cement, steel, asphalt, heavy machinery—produces between 250,000 and 350,000 tonnes of CO₂e, and that figure rises when debris clearance and disrupted supply chains are considered. In the Iran conflict, the initial $11.3 billion could have financed large‑scale clean‑energy projects, yet the prevailing financing models still favor carbon‑intensive construction. This disconnect is amplified by the absence of mandatory war‑related emissions reporting in the Paris Agreement, leaving a critical gap in climate governance.

Integrating systematic carbon accounting into both military budgeting and post‑conflict reconstruction offers a pragmatic route to close that gap. International standards such as ISO 14064‑1, combined with emerging climate‑linked financing criteria from multilateral development banks, can make emissions data a prerequisite for aid and investment. Transparent accounting would not only enable accurate liability assessments—potentially informing reparations and ecocide litigation—but also steer reconstruction toward low‑carbon designs, aligning recovery efforts with global net‑zero ambitions. As the climate system approaches irreversible thresholds, ignoring the emissions of war is no longer an option for policymakers or investors.