Comparing temperature-related mortality impacts of cool roofs in winter and summer in a highly urbanized European region for present and future climate

Helen L Macintyre; Clare Heaviside; Xiaoming Cai; Revati Phalkey

doi:10.1016/j.envint.2021.106606

Comparing temperature-related mortality impacts of cool roofs in winter and summer in a highly urbanized European region for present and future climate

Environ Int. 2021 Sep:154:106606. doi: 10.1016/j.envint.2021.106606. Epub 2021 May 7.

Authors

Helen L Macintyre¹, Clare Heaviside², Xiaoming Cai³, Revati Phalkey⁴

Affiliations

¹ Climate Change and Health Group, Centre for Radiation Chemical and Environmental Hazards, Public Health England, Chilton, Oxon OX11 0RQ, UK; School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK. Electronic address: Helen.Macintyre@phe.gov.uk.
² Institute for Environmental Design and Engineering, University College London, Central House, 14 Woburn Place, London WC1H 0NN, UK.
³ School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
⁴ Climate Change and Health Group, Centre for Radiation Chemical and Environmental Hazards, Public Health England, Chilton, Oxon OX11 0RQ, UK; Division of Epidemiology and Public Health, School of Medicine, University of Nottingham City Hospital, Hucknall Road, NG51PB Nottingham, UK; Heidelberg Institute for Global Health, University of Heidelberg, Im Neuenheimer Feld 130.3 69120 Heidelberg, Germany.

Abstract

Human health can be negatively impacted by hot or cold weather, which often exacerbates respiratory or cardiovascular conditions and increases the risk of mortality. Urban populations are at particular increased risk of effects from heat due to the Urban Heat Island (UHI) effect (higher urban temperatures compared with rural ones). This has led to extensive investigation of the summertime UHI, its impacts on health, and also the consideration of interventions such as reflective 'cool' roofs to help reduce summertime overheating effects. However, interventions aimed at limiting summer heat are rarely evaluated for their effects in wintertime, and thus their overall annual net impact on temperature-related health effects are poorly understood. In this study we use a regional weather model to simulate the winter 2009/10 period for an urbanized region of the UK (Birmingham and the West Midlands), and use a health impact assessment to estimate the impact of reflective 'cool' roofs (an intervention usually aimed at reducing the UHI in summer) on cold-related mortality in winter. Cool roofs have been shown to be effective at reducing maximum temperatures during summertime. In contrast to the summer, we find that cool roofs have a minimal effect on ambient air temperatures in winter. Although the UHI in summertime can increase heat-related mortality, the wintertime UHI can have benefits to health, through avoided cold-related mortality. Our results highlight the potential annual net health benefits of implementing cool roofs to reduce temperature-related mortality in summer, without reducing the protective UHI effect in winter. Further, we suggest that benefits of cool roofs may increase in future, with a doubling of the number of heat-related deaths avoided by the 2080s (RCP8.5) compared to summer 2006, and with insignificant changes in the impact of cool-roofs on cold-related mortality. These results further support reflective 'cool' roof implementation strategies as effective interventions to protect health, both today and in future.

Keywords: Adaptation and mitigation; Climate change; Cool roofs; Temperature exposure; Urban health; WRF.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cities
Climate Change
Cold Temperature*
Hot Temperature*
Humans
Seasons
Temperature

Grants and funding

WT_/Wellcome Trust/United Kingdom