We examine how two factors – climate change and urbanization – influence the future population exposure to four types of climate extremes in the continental U.S.: hot days, cold days, heavy rainfalls, and severe thunderstorm environments. Unlike previous studies, we consider how urban land change affects regional climate projections nationally.
We find that urban land effects can decrease as well as increase population exposures to climate extremes, and urban land effects can decrease population exposures in urban centers where climate effects increase exposures, including heat extremes at the city scale. We also conclude that the city-scale urban effect seen here can only be a result of urban land patterns and changing climate-urban-land interactions. The next steps include identifying the characteristics of the spatial arrangement of a city that makes it more or less resilient to future climate extremes so that this information can be used in future urban planning.
We examine how changes in urban land extent, population, and climate will respectively and collectively affect spatial patterns of future population exposures to climate extremes (including hot days, cold days, heavy rainfalls, and severe thunderstorm environments) across the continental U.S. at national, regional, and city scales at the end of the 21st century. Our results show that the spatial arrangement of urban land can have a moderating effect on the exposure of people to climate extremes, even in the case of heat extremes, and that the shape and distribution of urban land matter more than the total amount of urban land. Based on our results, we propose some initial ideas for incorporating long-term climate resilience into urban and regional land-use system planning, and we strongly encourage further exploration of optimal spatial urban land configurations that can effectively reduce the exposure of people to climate extremes throughout the 21st century.