Urban green infrastructure delivers carbon benefits primarily through microclimate cooling

Urban green infrastructure (UGI) is widely valued for its carbon sequestration capacity, yet this conventional framing overlooks a potentially dominant climate pathway: indirect carbon avoidance through microclimate cooling and reduced air conditioning demand. The absence of standardized methods to convert cooling benefits into carbon-equivalent metrics has prevented their integration into urban carbon accounting. Here, we developed the Cooling-Carbon Integration (CCI) framework to quantify both carbon sequestration and carbon avoidance from vegetation-driven cooling. Using a local case study with contrasting vegetation scenarios and a 37-city global database spanning six continents and seven climate zones, we demonstrate that carbon avoidance accounts for approximately 84% of total carbon benefits, exceeding sequestration by 4–25 times. The framework’s core metric exhibits climate independence and geographic universality, enabling standardized cross-city comparison without climate-specific calibration. Validated transformation pathways allow practitioners to convert existing datasets to the standardized framework without new field measurements. These findings reveal that UGI functions primarily as a cooling-carbon resource rather than a carbon sink, providing a methodological foundation for integrating cooling benefits into urban carbon asset inventories and climate action planning. • Carbon avoidance through cooling accounts for 83.7% of total carbon benefits • Biotic Cooling Score provides climate-independent metric across 37 global cities • Local validation reveals 134 tCO 2 e ha -1 yr -1 in avoided cooling emissions • Transformation pathways convert existing indicators to standardized framework • Cooling-related carbon benefits exceed sequestration by 4–25 times