Climate change increases the frequency and intensity of heatwaves, amplifying heat-related health risks in cities worldwide. Inequities in heat vulnerability arise from disparities in heat exposure, built and natural environments and population attributes that impact heat sensitivity, and socio-economic determinants of adaptive capability. A lack of internationally consistent and accessible heat vulnerability metrics creates barriers to assessing inequities and benchmarking urban heat vulnerability between cities worldwide. To address this need, we developed the Global Urban Heat Vulnerability Index (GUHVI), applicable to cities worldwide, using open data to identify spatial inequities in heat vulnerability at the neighbourhood scale. Built from an Australia-specific heat vulnerability index, the evidence-informed framework developed for the GUHVI evaluates heat exposure, heat sensitivity and adaptive capability to holistically assess heat vulnerability. Quantitative validation for eight Australian cities demonstrated strengths of the GUHVI in spatial resolution and assessment coverage of the grid-based framework. Qualitative validation for nine diverse cities internationally was performed in collaboration with local subject matter experts with knowledge of each city context. The GUHVI addresses critical gaps in existing methods by enabling systematic and comparable measurement of heat vulnerability in diverse cities internationally. Available through our customizable open-source global indicator software, the GUHVI provides evidence on modifiable risk factors of urban heat vulnerability, to inform targeted adaptation strategies that promote climate resilience and reduce health impacts from heat.

Large public urban green spaces (LPUGS) provide multiple health and environmental co-benefits by mitigating urban heat, improving air quality and biodiversity, and promoting physical activity, social interactions, and mental wellbeing. There is a lack of accessible, evidence-informed, and internationally validated LPUGS indicators to assist with benchmarking and monitoring progress toward healthy and sustainable cities globally. This study developed and validated internationally applicable spatial indicators of LPUGS availability and accessibility that are directly relevant to health and sustainability outcomes. For 13 cities across 10 middle- to high-income countries, we identified LPUGS ≥ 1 ha by fusing OpenStreetMap and satellite-derived Normalized Difference Vegetation Index data, and estimated residents' access within 500 m pedestrian network distance. We conducted a two-step validation process with local collaborators in each city. Our indicator methods identified LPUGS with greater than 80% accuracy for 12 of the 13 cities, and comparisons against official local reference data for four cities further demonstrated validity. While some open data limitations were identified, the indicators address critical gaps in existing methods by enabling standardized and comparable measurement of LPUGS in diverse cities internationally. Our customizable open-source global indicator tools can inform evidence-based green space planning for urban health and sustainability.

Cities are major contributors to global greenhouse gas emissions, and urban residents are experiencing escalating health impacts from climate change. It is therefore essential that city planning focuses on creating resilient, healthy built environments. This research explored the key determinants of healthy, climate resilient cities and identified indicators that could inform evidence-based planning internationally. We conducted a scoping review of academic and grey literature on healthy and climate resilient cities indicators. We identified three groups of determinants and indicators: climate hazard-specific, general resilience to climate hazards, and policy-specific. Across these groups, there were 12 categories of determinants, and 371 indicators. There was some consensus about urban heat, air pollution and flood being key climate-related health hazards, and the importance of green space; building quality; access to diverse amenities; low-carbon transport; and policymaking processes that promote urban climate resilience. However, the number and diversity of indicators may provide limited guidance to researchers and policymakers about optimal measures of healthy, climate resilient cities. We highlight specific gaps in current indicators and measurement considerations, including the need to validate indicators for cities internationally. Indicators that measure urban adaptive and transformative capacity are needed to track and guide policy progress towards healthy, climate resilient cities.