City-level temperature reduction from street green space by city typology and climate zone

Vegetation in the street can lower temperatures at neighbourhood level and reduce heat stress for pedestrians. Street green spaces (SGS) is thus an urgently needed nature-based solution for adapting to a warming climate, and also has some ability for carbon uptake. This local solution has global potential, but the cooling potential of street green space depends on local context, urban form and climate zone, among others. Here, we provide estimates of cooling potential of SGS for different climate zones, world regions and city type oriented along a typology recently provided. We find that peak wet bulb globe temperatures are relevantly reduced, and that the effect is greatest for large cities in the tropics and in temperate climates. Cooling from vegetation can only moderate the effect of global warming, not compensate for it. Carbon sequestration potential remains limited at 0.1 Gt CO2/yr, possibly double, if soil carbon is included, with high uncertainties. Street green will continue to be invaluable for local quality of life and be one contributor to reducing temperatures, but will not replace larger climate mitigation efforts.