Cities across the globe are increasingly using materials such as concrete, which store more thermal energy than natural materials and absorb sunlight rather than reflecting it, warming their surroundings. This urban heat island (UHI) effect has consequences on health, ranging from heat exhaustion to cerebrovascular events and circulatory failures resulting in death. Compounding the challenge is that the impact of extreme heat on health is uneven; it is shaped by both biological and social determinants of health. This brief argues that the path to heat equity requires bold policy action: Cities must revolutionise their approach to emissions control and environmental preservation to prevent catastrophic heat impacts on vulnerable populations.
In 2008, for the first time in human history, more people globally lived in cities than in rural areas. This global shift toward urbanisation, which began during the Industrial Revolution, has not only transformed how we live, build, and connect with each other, but has also fundamentally altered the earth’s climate.
Cities are increasingly using materials such as concrete, which store more thermal energy than natural materials and absorb sunlight rather than reflecting it, warming their surroundings. This effect, amplified by heat from vehicles and industry, creates urban heat islands (UHIs)—city zones that are significantly warmer than neighbouring rural areas. While the UHI effect currently averages between 2 and 4°C worldwide, this phenomenon is expected to intensify with worsening climate change. According to the IPCC’s Sixth Assessment Report, global surface temperatures are projected to rise by anywhere from 1.4°C to 4.4°C by 2100 under various scenarios. In urban areas, this warming will be amplified by the UHI effect, potentially leading to temperature differences of up to 8-10°C between cities and their surrounding areas by mid-century.
This paper can be accessed here.
This paper is authored by Nitya Mohan Khemka, ORF, New Delhi.