Responding to a recent report by the Delhi-based Sustainable Futures Collaborative (SFC), which has raised serious concerns about the preparedness of nine Indian cities, including Mumbai, for escalating heat waves, experts have suggested that the specific causes behind rising temperatures before policymakers can formulate effective mitigation measures. They also emphasised that green cover expansion must be prioritised to enhance urban resilience against extreme heat.
A solitary drinking water vendor braves the heat while plying his trade at Girgaon Chowpatty on March 12. Pic/Satej Shinde
Co-Authored by experts from King’s College London, Harvard University, Princeton University and the University of California, Berkeley, the study reveals that these high-risk cities rely heavily on short-term, reactive measures—such as emergency water distribution and hospital preparedness—rather than long-term, sustainable solutions to combat rising temperatures.
Heat vulnerability
“Mumbai is one of nine cities included in this study. It is already experiencing early and longer-lasting heatwaves. We chose Mumbai for our study because of its high population [12.44 million in the Mumbai Metropolitan Region, according to Census 2011] and the high increase in the number of extreme Heat Index [a measure of the combined effect of temperature and humidity] days relative to a historical baseline. Our climate modelling suggests that the city will see a sharp rise in these days as global temperatures breach the 1.5°C threshold,” the study states.
A fruit vendor cools off creatively near Kurla Terminus. Pic/Anurag Ahire
The researchers point out that Mumbai’s combination of high temperatures and extreme humidity levels exacerbates the city’s heat risk. Mumbai’s heat response is primarily guided by Maharashtra’s State Heat Action Plan (HAP) and the Mumbai Climate Action Plan. While these list key actions for different departments before, during and after a heatwave, experts argue they do not adequately emphasise proactive, long-term mitigation efforts.
What experts say
Dr Y Nithiyanandam, professor and head of Geospatial Research Programme at Takshashila Institution, Bengaluru, emphasised the critical need to identify causative factors before cities develop mitigation plans to address heat impacts. He stated, “Heat impact source in urban areas manifests in two primary forms: the urban heat island (UHI) effect and heatwave areas manifests in two primary forms: the urban heat island effect and heatwaves.
A boy tries to beat the heat on Juhu beach on March 16. Pic/Ashish Raje
The first is the local effect, and the second is the regional effect. Urban agglomerations are grappling with extreme heat, raising questions about whether these temperature increases stem from local influences or global climate change. The answer is not simple. However, to understand urban heat and mitigate its effects to a certain degree, we must analyse the factors contributing to increased temperatures, which ultimately affect the daily lives of citizens.”
He highlighted the necessity of narrowing down the problem in urban areas and identifying the specific causes behind rising temperatures. Policymakers must first comprehend these underlying causes before they can formulate effective mitigation measures.
The foliage of trees in a Powai garden provides shade. Pic/Atul Kamble
“In a city like Mumbai, rapid construction, an increase in impervious surfaces, a shrinking green cover, and an increase in vehicular traffic contribute to rising temperatures. Global warming exacerbates the situation. Cities experiencing local and global heat stress are particularly vulnerable. The impact is especially severe on the elderly, infants and those with comorbidities. Heatwaves, unlike air pollution, act as a silent killer while air pollution has visible indicators and identifiable sources. Heat is often perceived as an unavoidable natural phenomenon with no direct accountability,” Dr Nithiyanandam said.
Mitigation methods
The expert added, “A classic mitigation approach involves increasing green cover and expanding water bodies. However, there are practical challenges; how much green cover can realistically be increased in dense urban settings? Water shortages further complicate the situation, though treated wastewater could potentially be used for ground and road sprinkling to cool down urban spaces. The feasibility of such measures for urban civic bodies remains a concern.”
A woman shields her son from the heat in Kandivli. Pic/Nimesh Dave
Underlined the importance of identifying primary heat sources in cities, he said, “Vehicular emissions account for 20-30 per cent of anthropogenic heat in cities, making them the second-largest contributor after buildings. Waste heat generated by traffic significantly adds to urban temperatures.”
Dr Nithiyanandam pointed to mitigation strategies, such as using heat-resistant building materials, low heat emission technologies, making building facets which are less conductive of heat, improving ventilation, promoting urban agriculture, and developing rooftop and vertical gardens, as potential solutions and more importantly identifying suitable solutions for different urban pockets with respect to the causative factors.
However, he emphasised that the most urgent need is a well-structured Heat Action Plan. He said: “The first step is to identify causative factors and demarcate areas experiencing the most severe heat impact. Increasing vegetation cover using geospatial techniques, improving urban planning, and implementing sustainable cooling strategies are crucial for long-term mitigation.”
Mahesh Palawat, vice-president of meteorology and climate change at Skymet Weather, said, “Cities like Mumbai are becoming increasingly vulnerable to heatwaves and the UHI effect. The rapid expansion of two-tier and three-tier construction, along with unchecked urbanisation, is exacerbating things. The loss of green cover, depletion of groundwater, and continuous concreting further intensify heat impacts. This January was one of the hottest on record, followed by heatwaves in February and March, clear indicators of worsening climate conditions. To mitigate the effects of extreme heat, cities like Mumbai must prioritise increasing their green cover. Expanding urban greenery helps regulate microclimates, reduce the UHI effect, and improve air quality, making cities more resilient against rising temperatures.”
How is Mumbai preparing
In April 2023, heatstroke and sunstroke claimed the lives of 14 people during the Maharashtra Bhushan award ceremony in Navi Mumbai’s Kharghar. The event, held in an open-air setting, was organised to honour social activist and reformer Appasaheb Dharmadhikari. The incident triggered a widespread debate on government priorities and its preparedness to tackle the escalating heat crisis. In response to subsequent heatwave alerts this year, the Brihanmumbai Municipal Corporation (BMC) issued a comprehensive set of guidelines on March 10 to mitigate heat-related risks and safeguard public health.
A looming crisis
The study’s authors caution that unless Mumbai and other Indian cities prioritise long-term resilience measures, they will see an increase in heat-related. “These findings are a warning about the shape of things to come. With the ongoing retrenchment of global decarbonisation efforts, it will fall upon countries in the Global South to rapidly adapt to a hotter, more dangerous future. While progress on systems to respond to ongoing heat waves is both necessary and urgent, equal attention needs to be paid to gearing up for the future. Many of the long-term risk reduction measures we focus on will take several years to mature. They must be implemented now, with urgency, to have a chance of preventing significant increases in mortality and economic damage in the coming decades. At its core, this calls for the re-imagination of how India’s cities expand and develop,” said Aditya Valiathan Pillai, visiting fellow at Sustainable Futures Collaborative and doctoral researcher at King’s College London.
Dangerous combo
Lucas Vargas Zeppetello, assistant professor at the University of California, Berkeley, emphasised the unprecedented nature of the heat crisis, stating, “With increasing global mean temperatures, it’s imperative to prepare for extremely dangerous combinations of temperature and humidity that have no historical precedent to become more common. Pre-emptive, long-term strategies for dealing with heat are central to this effort.” Harvard University’s Alexandra Kassinis added, “Exposure to extreme heat and co-occurring humidity threatens lives and livelihoods. A shift to future-oriented, long-term, and informed planning is vital for meaningful preparation and adaptation.”
Study’s findings
The SFC study was based on 88 interviews with city, district, and state government officials responsible for heat action implementation in these nine cities. The research included discussions with representatives from disaster management, health, city planning, and labour departments, as well as city and district administrators.
The report highlights that the short-term solutions by the governments are crucial but warns that they are insufficient in addressing the escalating risks posed by climate change-driven heat waves. Mumbai’s Heat Action Plan and related strategies lack a robust focus on long-term resilience, such as expanding urban green cover, targeted cooling interventions for the most exposed populations and infrastructure strengthening, including the city’s electricity grids and fire services. The study also highlights institutional gaps, weak coordination among local bodies, and chronic underfunding for structural interventions, which further limit Mumbai’s capacity to build lasting resilience against extreme heat.
The SFC report is the first systematic assessment of heat resilience measures across multiple Indian cities, examining the implementation of long-term protections in Bengaluru, Delhi, Faridabad, Gwalior, Kota, Ludhiana, Meerut, Mumbai and Surat, which are home to over 11 per cent of India’s urban population.
A call for action
The report calls for a fundamental shift in India’s approach to heat governance. Ishan Kukreti, programme lead at Sustainable Futures Collaborative, pointed out, “Our findings show that disaster governance at the sub-national level in India is still driven by the logic of providing ex-post-facto relief measures. Such an approach will fall short in limiting the impacts of extreme heat as the world warms. This calls for an urgent need to complement these measures with proactive, long-term risk mitigation measures which will build resilience of institutions and communities in the face of risks posed by extreme heat.”
Tamanna Dalal, research associate at Sustainable Futures Collaborative, said, “These findings paint a dire picture of India’s unpreparedness for an increasingly unliveable future that is already at its doorstep. The current reliance on short-term relief measures, while necessary, will not be enough as temperatures continue to rise. We need immediate, structural interventions to redesign our cities and build institutions that safeguard vulnerable populations.”
BMC’s precautionary measures
>> Even if you’re not feeling thirsty, stay hydrated.
>> Regularly drink oral rehydration solution, buttermilk, coconut water, lemon water, or traditional cooling drinks like torani (rice water) to replenish fluids.
>> Refrain from consuming alcohol, tea, coffee, or carbonated drinks, as they contribute to dehydration.
>> Opt for light-coloured, breathable cotton garments.
>> When stepping out, wear sunglasses, a hat/umbrella, and appropriate footwear.
>> Always keep a water bottle with you.
>> If you work outdoors, make sure to use a hat, umbrella or a cotton cloth to cover your head and face.
>> Apply a wet cloth to your head, neck, face, and limbs to stay cool.
>> Use curtains, shutters, or sunshades during the day, and keep windows open at night for ventilation.
>> Bathe with cold water and use fans or wet clothes to regulate body temperature.
>> Avoid high-protein or stale food as it generates additional body heat.
>> Keep pets and stray animals in shaded areas and ensure they have adequate water.
>> Do not leave children or pets in parked vehicles as interior vehicle temperatures can rise rapidly, leading to fatal heatstroke.
Citizens urged to follow guidelines
>> The BMC has urged citizens to adhere to essential heatstroke prevention measures.
>> According to the India Meteorological Department, heatwave conditions are expected to persist until March 11, with a likelihood of repeated occurrences throughout March and April.
>> To address the challenges posed by heatstroke and severe heat-related illnesses, BMC Commissioner Bhushan Gagrani and Additional Municipal Commissioner (Eastern Suburbs) Dr Amit Saini have instructed civic authorities to implement preventive and emergency response measures for Mumbai residents.
SCF’s recommendations
Institutional changes
Strengthen HAPs in local governments: Institutionalise long-term actions, mandate vulnerability assessments, and identify urban heat islands for targeted interventions.
Leverage disaster mitigation funds: Utilise national and state disaster mitigation funds to finance long-term heat risk reduction projects.
Empower heat officers: Ensure chief heat officers (CHOs) have the authority and institutional backing to address systemic issues effectively.
Capacity building
Targeted training for HAP Implementation: Launch a multi-year programme to train officials in India’s most heat-vulnerable cities, starting with a high-impact group and expanding over time.
Establish dedicated disaster management roles: Create permanent, funded positions in climate-vulnerable districts to focus on long-term risk mitigation.
Tech and innovation
Implement an active cooling programme: Provide subsidies or large-scale purchase schemes for energy-efficient ACs in the most heat-prone urban areas and develop a national initiative to equip state and city officials with climate projections to better prepare for extreme heat conditions.
What to do if someone experiences heatstroke symptoms?
Move the person to a cool, shaded place, wipe them with a wet cloth, sponge their body and pour normal-temperature water on their head to cool them down; provide fluids; seek immediate medical assistance as heatstroke is life-threatening; rush the affected individual to the nearest hospital or health centre without delay.
Source: BMC
