EGU25-10425, updated on 15 Mar 2025
https://doi.org/10.5194/egusphere-egu25-10425
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
Cooling down urban green spaces in a future climate
Yuxin Yin1,2, Gabriele Manoli2, and Lauren Cook1
Yuxin Yin et al.
  • 1Department of Urban Water Management, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland
  • 2Laboratory of Urban and Environmental Systems, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland

Climate change is leading to an increase in urban heat, posing a threat to both humans and biodiversity. Urban green spaces (UGS), such as parks and gardens, have been shown to be cooler than surrounding areas, providing respite for city residents and habitat for many species. However, in a future, hotter climate, it is unclear whether UGS will maintain temperatures cool enough to support both species and human tolerances. The goal of this study is to evaluate how the microclimate conditions of UGS will be altered under climate change and what strategies are most effective to maintain their cooling effect under such conditions. To do so, we used a microclimate model (UT&C) to simulate air temperature, thermal comfort and other relevant variables within 15 urban green spaces across three Swiss cities (Zurich, Geneva and Lugano) under historical and future climate conditions. All models, validated using data collected summer of 2023, show good predictive performance for air temperature and surface temperature (R2 = 0.61 to 0.97). Future climate data for the 2080 decade was obtained from the COSMO-CLM convection permitting model under RCP 8.5 and bias-corrected to the station scale. Scenarios incorporating the five vegetation parameters most relevant to thermal comfort - leaf area index, ground vegetation coverage, albedo, tree height, and tree coverage - were developed and assessed for their effectiveness in mitigating temperature increases in a future climate.

Preliminary results for Zurich show that the ambient air temperature in the summer months is expected to increase by 1.6°C on average by 2080 compared to 2023. The UGS with current vegetation properties is expected to cool the air temperature by 0.2 °C on average. Although unable to offset the increase in temperature due to climate change, increasing the fraction of ground vegetation is the most effective solution, cooling by up to 1.3 °C. The remaining alterations were less effective, with some even increasing the temperature with respect to the baseline scenario (no change in vegetation properties). Future work will confirm the generalizability of these findings with a comparison across all UGS and cities. Overall, this study provides insights into the adaptive management of urban green spaces for both humans and biodiversity in the face of climate change.

How to cite: Yin, Y., Manoli, G., and Cook, L.: Cooling down urban green spaces in a future climate, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10425, https://doi.org/10.5194/egusphere-egu25-10425, 2025.