Adapting while mitigating: quantifiable contributions of ecosystem services and carbon offset to climate resilience in cities

Urban ecosystem services and associated carbon offsets are critical to enhancing cities' climate resilience across ecological, social, and economic dimensions, yet their collective impact remains empirically underexplored. This gap hinders the development of evidence-based policies for urban climate adaptation. The uncertainty stems from a lack of comprehensive understanding regarding how different ecosystem services and carbon offsets interact with urban development and climate change impacts. This study investigates the extent to which ecosystem services and carbon offset capacity affect ecosystem-based climate resilience (ECR) in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA). Its principal innovation lies in integrating the InVEST model with urban three-dimensional spatial configurations to quantify key ecosystem functions and their spatial heterogeneity. Contributing factors of ECR are examined using a spatial econometric analysis. The results show that nearly half of GBA districts achieve carbon offset rates of 80% or higher. Heat mitigation and habitat quality emerge as the most critical ecosystem services for ECR, contributing 15–30% and 20–35%, respectively. Notably, areas with higher carbon offsets do not necessarily exhibit higher ECR. In Zhuhai and Macao, high ECR levels are maintained despite lower carbon offset rates, underscoring the role of diverse ecosystem services. Our findings highlight the need to align ecosystem-based strategies with urban spatial forms to maximize carbon offsets and strengthen climate resilience across ecological, social, and economic dimensions.