By Sanjay Seth and Yatin Choudhary
Cities across India are experiencing record-breaking temperatures, intensified both by climate change and the urban heat island effect.
By 2047, more than half of India’s population will be living in urban areas.
This rapid urbanisation will require a significant expansion in infrastructure, with the India Energy Security Scenarios 2047 report projecting nearly 40 billion square meters of additional residential and commercial building spaces in the next two decades.
This urban growth comes at a cost — particularly in terms of climate.
According to the Indian Meteorological Department, 2024 was one of the hottest years in India’s recorded history, and 2025 has already surpassed seasonal norms with early, prolonged heatwaves across northern India.
April alone triggered multiple yellow and orange alerts, with temperatures climbing 4–5°C above normal, a spike directly linked to anthropogenic climate change.
Even minimum nighttime temperatures are rising — a worrying trend.
From July to October 2024, the country recorded the highest average monthly minimum temperatures since 1901, with anomalies reaching +1.78°C.
Hot nights mean little respite for residents, especially the urban poor, who are unable to afford cooling appliances and often live in high-density areas with limited green or open spaces.
The urban fabric — dominated by dense buildings and paved surfaces — absorbs and retains heat, raising temperatures by 3–5°C in core city zones compared to surrounding rural areas.
Air conditioners, while offering individual relief, only contribute to ambient heat. For the most vulnerable communities, particularly those living in the high density areas of cities with outdoor occupations and the Below Poverty Line (BPL) category, this becomes a matter of survival.
Human cost of warming
A 2023 peer-reviewed study for quantifying the human cost of global warming found that in a world 2.7°C warmer, around 600 million Indians would face severe health risks. However, limiting the temperature rise to 1.5°C—a reduction of 1.2°C—could reduce the at-risk population by 85 percent, leaving only 90 million Indians severely affected.
India began recognising heat as a disaster risk in 2015, with the India Meteorological Department, National Disaster Management Authority, and others supporting Heat Action Plans across 23 states.
These plans focus on emergency response and preparedness, particularly by urban local bodies. They also highlight the need for measures to reduce urban heat in the long term.
In the wake of urbanisation India needs to rapidly evolve its capacity to address the climate risk of urban heat. Efforts to assess cities and districts for their preparedness to address climate change and heat stress are gaining the attention of states and urban local bodies .
The National Guidelines on Heatwaves advocate for mitigation strategies such as increasing green cover, implementing cool roofs, and adopting permeable paving. These cost-effective interventions with long-term benefits can be termed as smart surfaces for mitigating urban heat.
Complementary efforts like the India Cooling Action Plan (2019) and addendum to guidelines under Model Building Bye-laws for addressing urban heat (2024) and Energy Conservation Sustainable Building Codes (2024) now include such heat resilience measures.
Yet, there is a critical gap in localised, data-driven solutions.
Data empowerment
Most urban heat strategies remain generic, failing to consider the unique vulnerabilities and climatic conditions of specific areas. Bridging this gap is the focus of the Smart Surfaces Coalition (SSC) — a global alliance of more than 40 research institutions.
The SSC has developed a Smart Surface Cost-Benefit Analysis Tool to identify localised heat mitigation solutions and assess their economic and health impacts. The tool uses accurate citywide surfaces data (area, albedo–a measure of reflectivity– and heat) and has the capacity to quantify and deliver on a citywide integrated cooling strategy,
This tool aims to empower local governments with precise, actionable data, enabling them to invest in strategies that cool cities, improve public health, and lower emissions.
Increasing smart surfaces such as vegetation cover, high solar reflective paints on roofs, light-coloured paver blocks on pavements, pervious (permeable) pavings etc. if adopted at a city-wide scale has the potential to decrease a city’s average temperature by more than 2°C.
This has been demonstrated in the analysis done for the city of Baltimore, USA, which led to the development of legislation to adopt smart surfaces which can lead up to 2.4°C (4.3 degrees F) reduction in temperature. Similar interventions are being planned in 12 more US cities and many other world cities.
Local mitigation strategies
Urban heat is a public health emergency, an infrastructure challenge, and a climate crisis rolled into one. To safeguard Indian cities and their most vulnerable populations India needs to adopt cost-effective long-term mitigation strategies at the city level.
To effectively mitigate urban heat, cities must transition from conventional materials to smart surfaces in both new developments and existing infrastructure.
For new buildings and city infrastructure, this involves revising design specifications and updating procurement policies to prioritise smart surface technologies for roofs, pavements, and limiting hard paved surfaces in landscapes. In existing structures, however, change must be driven by community engagement, advocacy, and, where feasible, the use of incentives.
Nature-based solutions—such as increasing urban vegetation—can complement smart surface adoption in both new and existing developments, providing additional cooling benefits and environmental co-benefits.
City-wide implementation of smart surfaces can offer significant relief to urban populations, particularly vulnerable groups most affected by extreme heat.
However, given the scale and complexity of such an undertaking, a data-driven, integrated approach is essential. This process should begin with identifying urban heat hotspots and gathering comprehensive data on land use, building types, socio-economic conditions, and the distribution of public and private spaces.
These insights will allow cities to tailor interventions to local conditions at city level as well as sub-city and neighbourhood levels and craft supportive policies that guide the large-scale rollout of smart surface solutions.
This article was jointly commissioned by TERI (The Energy And Resources Institute), GRIHA (Green Rating for Integrated Habitat Assessment) Council, and 360info.
Sanjay Seth is Senior Director, Sustainable Infrastructure Programme, TERI, and Vice President & CEO, GRIHA Council. Yatin Choudhary is Fellow, Sustainable Buildings Division, TERI.
Originally published under Creative Commons Attribution 4.0 by 360info™.
