“Global climate-driven trade-offs between the water retention and cooling benefits of urban greening” in Nature Communications (2022).

An open-access article published in Nature Communication 13:518 by Cuthbert et al. (2022) entitled “Global climate-driven trade-offs between the water retention and cooling benefits of urban greening” discusses that urban greening can potentially help mitigate heat-related mortality and flooding facing the >4 billion urban population worldwide. However, the geographical variation of the relative combined hydrological and thermal performance benefits of such interventions are unknown. Cuthbert et al. (2022) quantify globally, using a hydrological model, how climate-driven trade-offs exist between hydrological retention and cooling potential of urban greening such as green roofs and parks. Using a Budyko framework, they show that water retention generally increases with aridity in water-limited environments, while cooling potential favors energy-limited climates. Their models suggest that common urban greening strategies cannot yield high performance simultaneously for addressing both urban heat-island and urban flooding problems in most cities globally. Irrigation, if sustainable, may enhance cooling while maintaining retention performance in more arid locations. Increased precipitation variability with climate change may reduce performance of thinner green-infrastructure more quickly compared to greened areas with thicker soils and root systems. Their results provide a conceptual framework and first-order quantitative guide for urban development, renewal and policymaking.