Heat stress has emerged as a significant concern in major Indian cities. A detailed study by the Centre for Science and Environment (CSE) highlights how heat waves are becoming increasingly deadly due to rising temperatures, higher humidity levels, and urban expansion. The alarming trend is that cities are cooling less at night than they did in the past.
The study examined data from six prominent cities: Delhi, Mumbai, Kolkata, Hyderabad, Chennai, and Bengaluru over a 23-year period from January 2001 to April 2024. The findings underscore the critical importance of nighttime cooling, which offers respite from the intense daytime heat. Without adequate cooling at night, residents continue to suffer from heat stress, adversely affecting their health.
The phenomenon of heat stress is influenced by several factors, including air temperature, land surface temperature, and relative humidity. High humidity levels hinder the body’s natural cooling process through sweating, increasing the risk of heat-related health issues.
One major contributing factor is the "urban heat island effect," where cities register significantly warmer temperatures than their surrounding rural areas. This effect is exacerbated by concrete and other built-up areas that absorb and retain heat, leading to elevated urban temperatures.
Unregulated urban expansion and the loss of green spaces have further intensified heat stress. For instance, Chennai has experienced a nearly 14% reduction in green cover over the past two decades, while areas covered by concrete have doubled, contributing to elevated heat levels.
High temperatures and humidity compromise the body's ability to cool itself, resulting in heat stress and potentially fatal heat-related illnesses. The frequency of days with a heat index surpassing 41°C, posing severe health risks, has increased in cities like Kolkata and Chennai.
The CSE study suggests several measures to alleviate heat stress, including city-specific heat management plans, enhancing green cover and water bodies, improving the thermal comfort of buildings, and reducing waste heat from vehicles, air conditioners, and industrial activities. Other critical actions include strengthening scientific monitoring and devising emergency action plans to safeguard vulnerable populations during heat waves.
Kutos : AI Assistant!
