By Jianying Liao and Dr. Samuel Cai, Lecturer in Environmental Epidemiology, Health Sciences Department, University of Leicester, UK

Introduction

Due to climate change, record-breaking summer temperatures are increasingly reported across the world in recent years. Heatwaves have become more frequent and intense in some parts of the world, especially in urban areas, posing significant health risks. In summer 2022, 61,672 heat-related deaths (Ballester et al., 2023) were estimated in Europe. Globally, the year 2023 was the hottest year on record to date. While active cooling strategies such as air conditioning can potentially protect health from extremely hot weather, it will also cause a sharp increase in energy demand and, therefore, may contribute to the global warming effects. Moreover, there are accessibility and inequality issues here as not every household will be able to afford to air conditioning at home. Therefore, it is important to find sustainable, and potentially scalable, solutions to mitigating the adverse health impacts of extremely hot weather in the cities.

Nature-Based Solutions

As suggested in the 2023 Heat Resilience and Sustainable Cooling Report published by the UK Environmental Audit Committee, nature-based solutions (NBS) such as parks, trees, water bodies, and green infrastructure (e.g., green/reflective roofs, and shade provision) have significant cooling effects and potentially decrease heat-related deaths on a population level. For instance, green roofs provide thermal resistance to buildings during heatwave, cooling indoor temperatures by up to 15°C (Mihalakakou et al., 2023). Moreover, NBS can moderate factors that are potentially associated with heat-related deaths, including absorbing dust and particles in the air and improving air quality, absorbing sound waves and reducing noise levels, as well as boosting mental health and reducing psychological stress. However, challenges like long-term maintenance and high initial costs have hindered NBS promotion in some countries. Evidence from locally derived research is crucial to inform targeted NBS policies to reduce heat-related deaths through NBS.

Timely and Targeted Heatwave Warning Systems

Although mitigation measures such as NBS can reduce the deadly impacts of heatwave, these measures require time to implement at scale.   A timely, targeted heatwave warning system for the whole population, especially vulnerable groups, is critical to preventing the immediate health impacts of heatwaves. Children, the elderly, and people who are chronically ill, or of low-socioeconomic-status were identified as vulnerable to the adverse impacts of a heatwaves (Arsad et al., 2022). For these groups, providing bespoke messages is more effective in protecting their health during heatwave than issuing general heatwave warnings. This, however, would require intensive research in each of the subgroups among the populations to generate robust evidence to inform the warning system.

Community Engagement and Education

Reducing misinformation could save lives. Providing effective education on avoiding heat stress is a sustainable measure to significantly reduce avoidable deaths from heatwave. Public engagement and education should focus on directly communicating the threat of heatwave to health. Suggestions at the individual level should remain clear and simple, such as drinking enough water before feeling thirsty, wearing light-coloured clothes, and avoiding direct sunlight. The Heatwave Action Plan in western Sydney, Australia, calls for leaders of all levels of organizations to work together to raise awareness of urban heat issues and promote behaviour changes, supporting community engagement, education, and preparedness efforts (UN Environment Programme, 2021). By empowering individuals with knowledge and resources, we can significantly decrease avoidable deaths from heatwaves, fostering a more sustainable and resilient society.

Conclusion

In order to combat the escalating threat of heatwaves exacerbated by climate change, sustainable solutions offer promising ways to mitigate its adverse impacts in urban environments. Adopting nature-based solutions, implementing timely and targeted warning systems, and promoting community engagement and education are critical steps towards creating heatwave-resilient societies. By prioritising these measures, we can proactively address heatwave vulnerability and move towards a more sustainable future.

References:

1. Arsad, F. S., Hod, R., Ahmad, N., Ismail, R., Mohamed, N., Baharom, M., Osman, Y., Radi, M. F. and Tangang, F. (2022) ‘The Impact of Heatwaves on Mortality and Morbidity and the Associated Vulnerability Factors: A Systematic Review’, International Journal of Environmental Research and Public Health, 19(23). doi: 10.3390/ijerph192316356.
2. Ballester, J., Quijal-Zamorano, M., Méndez Turrubiates, R. F., Pegenaute, F., Herrmann, F. R., Robine, J. M., Basagaña, X., Tonne, C., Antó, J. M. and Achebak, H. (2023) ‘Heat-related mortality in Europe during the summer of 2022’, Nature Medicine, 29(7), pp. 1857-1866.
3. Mihalakakou, G., Souliotis, M., Papadaki, M., Menounou, P., Dimopoulos, P., Kolokotsa, D., Paravantis, J. A., Tsangrassoulis, A., Panaras, G., Giannakopoulos, E. and Papaefthimiou, S. (2023) ‘Green roofs as a nature-based solution for improving urban sustainability: Progress and perspectives’, Renewable and Sustainable Energy Reviews, 180, p. 113306.

UN Environment Programme (2021) Beating the Heat: A Sustainable Cooling Handbook for Cities. Available at: https://www.unep.org/resources/report/beating-heat-sustainable-cooling-handbook-cities (Accessed: 23 March).

Disclaimer: The views expressed in this piece are those of the author/s and do not necessarily reflect the views or policies of AIDMI.