Research published in The Guardian (March 2026) found the US caused $10 trillion in global climate damage since 1990 as the world's largest historical carbon emitter — about a quarter of that damage hits the US itself, but poorer nations absorb the rest disproportionately. This matters because it quantifies the historical responsibility wealthy nations bear for climate harms in developing countries, which is central to global climate negotiations and climate justice frameworks. The study doesn't address whether this $10 trillion figure includes all indirect economic cascades (supply chain disruptions, migration costs, conflict-driven losses) — the precise methodology behind the damage calculation could shift how we interpret these numbers.