EGU23-9892, updated on 25 Sep 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Assessing the impact of urban heat islands on the risks and costs of temperature-related mortality

Wan Ting Katty Huang1, Pierre Masselot2, Elie Bou-Zeid3, Simone Fatichi4, Athanasios Paschalis5, Ting Sun6, Antonio Gasparrini2,7,8, and Gabriele Manoli1,9
Wan Ting Katty Huang et al.
  • 1Department of Civil, Environmental and Geomatic Engineering, University College London, London, UK
  • 2Department of Public Health, Environments and Society, London School of Hygiene & Tropical Medicine, London, UK
  • 3Department of Civil and Environmental Engineering, Princeton University, Princeton, USA
  • 4Department of Civil & Environmental Engineering, National University of Singapore, Singapore
  • 5Department of Civil & Environmental Engineering, Imperial College London, UK
  • 6Institute for Risk and Disaster Reduction, University College London, London, UK
  • 7Centre for Statistical Methodology, London School of Hygiene & Tropical Medicine, London, UK
  • 8Centre on Climate Change and Planetary Health, London School of Hygiene & Tropical Medicine, London, UK
  • 9School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne, Switzerland

Ambient temperatures have an impact on human health, with unfavourably warm and cold conditions both associated with elevated mortality risk. By modulating the temperature in urban environments, urban heat islands (UHIs) can therefore both amplify the impact of heat and offer protection against cold weather. In this study, we quantify the impact of UHI on human mortality at 500m resolution for 85 European cities using air temperature simulations and age-dependent epidemiological temperature-mortality relationships for each city. On an annual basis, UHIs have weak net protective effects for most cities examined. This is due to the prevalence of cold to mild days in these cities when an increase in temperature is associated with slight reductions in mortality risk. On a daily basis, however, UHIs induce the greatest impact during heat extreme days, with a median of 39% increase in risk compared to a 7% reduction during cold extreme days. A valuation of such mortality risk reveals that the annual cost of UHI-related heat mortality is comparable to air pollution-related mortality costs as well as transit costs. Cities with Arid climates and Temperate Dry Summer climates in Southern Europe tend to experience the greatest protective UHI effects during cold extreme weather and the least adverse effect during heat extremes, while cities with Cold climates in Eastern and Northern Europe tend to benefit the least during cold extremes. Annually, the net impact of UHI is most strongly correlated with each city’s vulnerability to heat and cold and the ratio of warm vs. cold days in a year.

How to cite: Huang, W. T. K., Masselot, P., Bou-Zeid, E., Fatichi, S., Paschalis, A., Sun, T., Gasparrini, A., and Manoli, G.: Assessing the impact of urban heat islands on the risks and costs of temperature-related mortality, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9892,, 2023.