No single urban-cooling measure works alone at city scale — canopy, cool roofs and traffic reduction each chip away at the same heat-island problem.
temp_reduction ~ coverage * effectiveness
- City grid size — city blocks tracked for temperature and mitigation coverage.
- Mitigation measure coverage — share of blocks fitted with cool roofs, canopy or traffic reduction.
- Baseline urban heat — unmitigated heat-island intensity before any measures are applied.
- Measure effectiveness — how much each mitigation measure actually cools its block once installed.
Combining reflective roofing with expanded tree canopy has cut peak summer temperatures by 2-3°C in real pilot districts from Los Angeles to Athens.