Rising temperatures in Mumbai call for mitigation measures, but where are they?

Missing mitigation plan for heatwaves in mumbai

a man at a local train station in mumbai sits with his head in his hand
Mumbai's maximum temperature touched 40 degrees Celsius this month, marking a rise in the city's heat | Photo: Flickr, Attribution-NoDerivs 2.0 Generic (CC BY-ND 2.0)

Rekha, a fruit vendor in Kandivali east, has been selling fruits in the area for over 6 years now. Parked under a large umbrella that offers shade from the sun, she awaits customers. “The heat this year has been the worst in a long time, and it is only April. It will get worse,” she exclaims, adding that the recent heatwave in the city has also affected her business since customers don’t come out much and her fruits get spoiled in the scorching heat during the day. Rekha is also one of the many street vendors in Mumbai who conduct business at the risk of eviction by the Brihanmumbai Municipal Corporation (BMC), an additional loss in daily wages these days, she says. “I just manage, one has to.”

The last week of March 2022 was exceptionally hot for Mumbaikars, as the temperatures in the city were almost 40 degrees Celsius amid an ongoing heatwave affecting northwest, central (including Vidarbha) and west India (including Konkan, Marathwada and Madhya Maharashtra). This is expected to continue for another few days, according to the Indian Meteorological Department (IMD).

The unusual and early onset of high temperatures in the city has citizens alarmed. According to the IMD, a maximum daytime temperature of 33 degrees Celsius is considered normal, but a maximum temperature of 37 degrees Celsius, which is what Mumbai touched on March 24th, is considered a ‘heatwave.’ 

But, this is not the worst the city has experienced, nor is it new. On March 28th, 2021, the city’s temperature had reached 40 degrees Celsius, only a little under the maximum recorded temperature of 41.7 degrees Celsius, recorded on March 28th 1956.

A vulnerability assessment executed by the World Resources Institute (WRI India), a research organisation, found that the city would face two major challenges: rising temperatures and extreme rain events. A warming trend over 47 years was found, with an increase of 0.23 degrees Celsius per decade. 

But, some areas in the city find it hotter than others. Dharavi, for example, is usually five degrees hotter than its immediate neighbour, Matunga. “Within an area, there’s a temperature difference between (housing) societies with open spaces, landscaping, or trees, and those without,” Lubaina Rangwala, Senior Manager – Urban Development & Resilience, WRI, told Citizen Matters. Given that a large population of Mumbai resides in slum areas, the congestion, access to open spaces and green cover all contribute to the increased warming in those areas. The lack of green cover in Mumbai – currently only two major areas, Sanjay Gandhi National Park and the mangroves near the Thane creek make for the city’s green cover – also adds to warming.

Considering the continued pattern of heatwaves and increasing warmth in the city, why is Mumbai not more prepared?

a man in mumbai carries clay water dispensers on his head on a road
Mumbai currently lacks a comprehensive system in place to help citizens battle the scorching heat | Photo: Gopal MS, Mumbai Paused

Extreme summers: How can a city prepare?

The Urban Heat Island (UHI) effect, a warming phenomenon that occurs when an urban area is warmer than its surrounding rural areas, could shoulder some of the blame for rising temperatures in Mumbai. With about 40% of Mumbai’s green cover lost between 1991 and 2018, increasing Land Surface Temperatures under the backdrop of rapid construction is expected.


Read more: ‘Biodiversity zones that make Mumbai livable will vanish, if urgent measures are not taken’


Jayanarayanan Kuttippurath, a scientist from IIT-Kharagpur and the co-author of ‘Anthropogenic forcing exacerbating the urban heat islands in India’, told Scroll.in that building material used in construction play a key role in the UHI effect. “Changes in urban surfaces (impervious surface or changes in land use) modify the temperature of a city. Building material and surfaces such as asphalt absorb the sun’s heat, leading to an increase in surface temperatures and overall temperatures. Infrastructure can considerably alter the temperature of a region/city,” he said.

To introduce mitigation plans for heatwaves, the National Disaster Management Authority (NDMA) compiled the ‘National Guidelines for Preparation of Action Plan – Prevention and Management of Heat Wave’ report to offer mitigation strategies for Indian cities. As per its 2019 report, a comprehensive Heat Action Plan strategy would reduce heat-related deaths and establish community responsiveness to rising temperatures. Addressing the UHI effect, the report outlined that cities must assess their built environments for the identification of factors contributing to UHI magnitude. 

Medium-to-long-term measures as listed in the report:

  • Identification and evaluation of factors leading to a disproportionate increase in temperature within the city.
  • Generating a heatwave risk and vulnerability map for developing a strategic mitigation action plan.
  • Mapping hot spots in the city.
  • Measures like vertical gardens and fountains to reduce temperatures in hot spots.
  • Built environment assessments with educational and research institutions.
  • Allocate budget for research and development of heat action plan.
  • Incorporate findings from built environment assessments into urban design and policy.
  • Integrate heat action plan with the development plan.
  • Adhere to building codes in the city.

Additionally, the role of Urban Local Bodies (ULBs) in mitigation would be paramount, given their position in local environments. Strengthening their roles through measures such as decentralisation of urban development policymaking, capacity building of ULBs through educational institutions, collaborations between NGOs and other relevant organisations, and increasing funding for climate change mitigation are all pivotal.

Missing heat mitigation plans in Mumbai

In 2013, Ahmedabad became the first city in South Asia to implement a comprehensive Heat Action Plan (HAP) to tackle frequent heat waves, particularly in response to the disastrous month of May 2010 when over 4000 people lost their lives to rising temperatures. The HAP includes mitigation strategies to reduce the impact of heatwaves on the ground; on the livelihoods of people, on flora and fauna, etc. 

Ahmedabad’s civic body tied up with Georgia Institute of Technology, Rollins School of Public Health of Emory University, Indian Institute of Public Health, U.S.-based non-profit advocacy group Natural Resources Defense Council, and the U.K.-based Climate & Development Knowledge Network (CDKN) for the formulation of their plan, that included:

  • Community outreach initiatives
  • An early warning system that provides a seven-day early forecast of impending high temperatures
  • Training healthcare professionals to treat citizens for heat-related complications. 
  • Other measures like water supply in slum areas, open drinking water centres, sprinklers at crossroads and gardens, and altering timings in educational institutions all helped bring down deaths in the city. 

Building from the foundation laid by Ahmedabad, 11 states and 17 cities across India began developing their mitigation plans in 2018. Among other states was Maharashtra, where only two corporations, Nagpur and Chandrapur, made the HAP into effect. According to the NRDC, Maharashtra’s state-wide mitigation measures included wide awareness campaigns and revisions in school timings. Other efforts like consistent water supply were also included. However, there is little evidence of execution across the state, and a senior state official told Indian Express that the plan is solely on paper. In Mumbai especially, water supply continues to be a problem.

In Bhubaneshwar, as western Odisha struggled under 40 degrees Celsius in April 2022, the government issued guidelines to help people deal with the temperatures. Labourers have been asked to stay off work during the afternoons and water kiosks have been set up in different places. The Bhubaneshwar police have also been making announcements in many areas about precautions related to the heat. A vast awareness campaign by Odisha State Disaster Management Authority (OSDMA) aims to raise awareness among citizens about heat strokes, as part of their work toward a comprehensive HAP before the summer months.

The impact of HAP in the country has been significant. As per the NDMA, heat-related deaths in India dropped from 2,040 in 2015 to under 300 in 2019. Ahmedabad avoided an estimated 1,190 deaths only a year after implementing its HAP. Given the inevitable implications of a comprehensive mitigation plan for heatwaves, Mumbai is still behind in its planning.

Will the Mumbai Climate Action Plan make any difference?

On March 24th, Mumbai recorded a rise in temperatures after a few days of normalcy. At 38.2 degrees Celsius, the maximum temperature was 5.4 degrees above normal. Despite the fluctuations, the city doesn’t seem prepared for the heatwaves or their intensities, but an acknowledgment of rising temperatures was made clear in the recent Mumbai Climate Action Plan (MCAP).

Released on March 13th, the MCAP founded a 30-year roadmap for the city to combat the challenges of climate change through mitigation strategies. Ultimately aiming at a long-term target of net-zero emissions by 2050, the plan highlights short, medium and long-term targets in areas of sustainable waste management, urban greening and biodiversity, urban flooding and water resource management, energy and buildings, and air quality and sustainable mobility.

While the MCAP takes stock of all issues pointed out by the WRI and other studies, especially the need to act towards increasing warming in the city, it fails to apply lessons from HAP for a comprehensive mitigation plan, which is the need of the hour. Immediate solutions like Ahmedabad’s forecast system are not mentioned in the MCAP but could help the city greatly. 

“There is no accountability,” says environmentalist and director of NatConnect foundation BN Kumar. “The MCAP does not even consider all of Mumbai. In declaring net-zero emissions by 2050, is the report also saying that areas of Chembur, Vashi, and Navi Mumbai will be free of flooding?” On the need for water supply during heatwaves, he adds that the lack of enforcement of rainwater harvesting and decreasing mangroves and wetlands would add to the city’s ill-preparedness. 

“Better forecasting can be a way of current mitigation,” Dr A K Sahai, a scientist at the Indian Institute of Tropical Meteorology, Pune, told Citizen Matters, adding that forecasting can help a city execute short-term solutions like stopping daytime outdoor work or altering timings at parks.

Additionally, considering the fluctuations in temperature even within the city, solutions need to be more local than just city-wide. “If you allow a glass structure to come at the edge of the road and (if) the developer is not accountable for the heat generated on the road, then it’s a policy problem. The solutions can’t be city-wide, she adds. They have to be local.” says Lubaina. 

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About Saachi D'Souza 9 Articles
Saachi is an Associate Editor at Citizen Matters Mumbai