Cities around the world, especially in India, are grappling with some of the hottest March temperatures recorded in years. The western Indian city of Ahmedabad is working to address these deadly temperatures through a comprehensive resilience plan for heat waves—and a new cool roofs initiative focused on slum communities. Earlier this month, Ahmedabad launched its fifth Heat Action Plan—an early warning system to warn and protect citizens from the devastating health effects of extreme heat.
As part of the 2017 Ahmedabad Heat Action Plan, Mayor Gautam Shah and Municipal Commissioner Mukesh Kumar launched a city-wide initiative on cool roofs to provide access to affordable cooling for those who are more vulnerable to the health effects of extreme heat—Ahmedabad’s slum residents and urban poor. Building on our long term partnership, the Ahmedabad Heat Action Plan was developed and launched in collaboration with the Indian Meteorological Department (IMD), Indian Institute of Public Health, Gandhinagar (IIPHG) and NRDC.
Nearly 25 percent of Ahmedabad’s residents live in slum communities, according to the city. The nearly two million Ahmedabad residents living in slums have few options available to adapt to rising temperatures. This increases their vulnerability to heat and results in greater adverse impacts of extreme heat. In developing the heat action plan and through expert focus group discussions, the Ahmedabad Municipal Corporation along with NRDC and IIPHG identified the specific factors that increase the vulnerability of slum residents to extreme heat.
Key factors include risk factors such as lack of access to health information and strenuous outdoor work, in their home environments. Slum communities have fewer adaptation options since they often lack control over their home and work environments, with limited access to, and inability to afford, reliable electricity and cooling. Slum residents also have higher exposure to extreme heat because they are more likely to be exposed to heat since they live in homes constructed of heat-trapping materials with tin or tarp roofs, and their communities lack trees and shade. In an effort to strengthen resilience in slum residences, the Mayor of Ahmedabad ran an awareness campaign including promoting measures for evaporative cooling such as placing wet jute gunny sacks on the slum roofs to reduce temperatures in 2016.
Building on last year’s efforts, the Ahmedabad Municipal Corporation formally introduced a cool roof initiative as part of the 2017 Heat Action Plan. Highlights of the cool roofs initiative includes, the AMC will:
- Install at least 500 slum household roofs to cool roofs
- Convert public buildings to cool roofs, including municipal buildings and government schools, including in the city’s procurement criteria
- Release new information, education and communication (IEC) materials to build awareness on cool roofs
After releasing the new cool roofs initiative, Mayor Gautam Shah and the AMC led by example. The Mayor visited slums in the Usmanpura area started painting a roof with a white reflective paint himself. Several of the senior health and government officials, as well as partners including the NRDC and IIPHG, team rolled up our sleeves and started painting. The local residents were very engaged and eager to learn more.
Cool roofs are highly reflective surfaces that stay cool in the sun by minimizing heat absorption and emitting most of absorbed heat. Studies have shown that cool roof surfaces can be up to 30ºC cooler than conventional roof surfaces, and thereby, can reduce the indoor temperatures by 3-5ºC. When implemented on a large scale, cool roofs can reduce the urban heat island effect in a city and lower the energy bills of the entire city. Cool roofs include coatings and treatments such as lime-based whitewash, white tarp, white china mosaic tiles and acrylic resin coating, and provide an affordable solution for providing thermal comfort.
The focus on cool roofs stems back to the devastating 2010 heat wave in Ahmedabad, the impetus for the heat action plan. In 2010, temperatures peaked at 46.8ºC (more than 116ºF), a 50-year record high, in Ahmedabad. During the scorching heat wave, the city’s municipal hospital Shardaben Hospital experienced a dramatic increase in patients with heat-related illness including heat stress, heat strokes, and other respiratory and gastrointestinal illness. The neonatal ward (the unit treating newborn babies) was located on the top floor of the building at the time, under a black tar roof, creating an oven-like effect with temperatures even hotter than in the rest of the hospital. The hospital saw very high mortality in newborns that year. As part of the heat action plan, the hospital replaced the black tar roof to a white reflective china mosaic roof that reduced temperatures inside the hospital and helped provide thermal comfort.
Cool roofs are an affordable and smart solution that helps manage cooling demand and mitigate the impact of urban heat island effect. Solutions, such as the heat action plan and new cool roofs initiative, are critical to saving lives and addressing skyrocketing cooling demand in cities across India, as climate change continues to drive extreme temperatures.