Scalable quantification of three-dimensional material albedo reveals consistent cooling mechanisms and unequal heat mitigation potential

As global warming worsens urban heat, accurate urban heat modelling is key to cooling strategies, which traditionally overemphasises coarse land cover while overlooking detailed three-dimensional (3D) materials like building façades and roads. This study operationalised a high-throughput pipeline to quantify 3D material envelope information across five diverse United States cities: Boston, Chicago, Los Angeles, New York, and Seattle. We provided the first city-wide, street-level 3D material albedo dataset and revealed a consistent cross-city pattern: façade albedo shows a robust cooling association across diverse urban morphologies, supported by SHapley Additive exPlanations (SHAP) interpretation and counterfactual scenarios, whereas road albedo interacts nonlinearly with canyon geometry. Our findings suggest a previously unquantified material-geometry regime and indicate effective mitigation measures to prioritise the hottest low-density suburban areas where low-income households dominate; high albedo renewal can yield a cooling potential of up to 1.14 °C in Boston. This study highlights the critical role of 3D material albedo in urban heat, offering actionable insights for equitable climate adaptation.