Indian cities are simmering in their own waste heat
By Avikal Somvanshi
Delhi’s summers and monsoons are hotter by 3.6°C and 3.3°C on the heat index compared to the 1950s. An analysis by the Centre for Science and Environment, a New Delhi-based non-profit, of weather data for 2010-2017 reveals that average heat index of both the seasons has witnessed a steady upward trend.
The health costs of the heat island effect are massive. A study of excess mortalities in Asian cities due to urban heat island effects suggests that mortality increases by 5.8 per cent per 1°C temperature rise over a threshold of 29°C in Delhi.
At present, ACs are the most effective (and resource-intensive) means to cool indoor spaces to survive the urban hearth. However, rampant use of ACs is problematic as it adds fuel to the outdoor fire, making cities hotter.
Air conditioning is a key parameter of health problems due to heat waves because, on the one hand, it reduces mortality but, on the other hand, depending on the heat management, it can increase street temperature, thereby increasing the heat stress on people who don’t have access to an AC.