Proximity-based cities emit less mobility-driven CO2

In the pursuit of more environmentally sustainable urban areas, the 15-minute city model promotes active mobility by ensuring that essential services are reachable within a short walk or bike ride from home. Yet, its actual effectiveness in reducing car use and related carbon emissions remains debated. This study presents a large-scale data-driven analysis to evaluate the impact of service proximity to homes on CO2 emissions. Examining nearly 400 cities worldwide, we nd that, within the same city, areas where services are located closer to residents produce less CO2 emissions per capita from transportation. We establish a relationship between the proximity of services and CO2 emissions for each city. We then estimate potential emission reductions for 30 cities by optimising service locations to achieve more uniform accessibility and stronger adherence to the 15-minute paradigm. Our ndings indicate that improving the proximity of services can substantially reduce transport-related urban emissions.