The temperature in most city districts have always been higher than on the countryside. Buildings, roads, concrete and other hard structures absorb and re-emit the sun’s heat more than natural landscapes such as forests and water bodies.
Urban areas, where these structures are highly concentrated and vegetation or water is limited, become “islands” of higher temperatures relative to outlying areas. These zone are referred to as ‘urban heat islands’. This phenomenon is observed globally, also in India. This urban heating effect on top of the warming by climate change can have severe consequences. Climate change leads more frequent and intense heat waves. Urban areas already suffering from the heat island effect will bear the brunt of these extreme heat events.
Since India is fastly urbanising, this is a growing concern for authorities at national and local level. India’s urban population is expected to double by 2050 to 800 million, from 420 million in 2015. The phenomenon of urban heat island risk to threaten not only the wellbeing of the city dwellers, but also their health.