Melting the potential of an economy on the rise

This article is authored by Aun Abdullah, programme director, Sustainable Urbanisation, Lodha Foundation.

Urban heat is often dismissed as "just summer," accepted as a seasonal inevitability; but the stifling heat radiating from pavements and walls, along with waste heat from millions of air conditioners, idling engines, and industrial processes long after sunset, is not natural weather. It is a man-made challenge.

Climate crisis

More importantly, it is an economic one. We are effectively paying a thermal tax on our cities--a hidden cost that quietly erodes productivity, strains labour, and undermines growth.

We have inadvertently designed our cities to become heat traps. Through excessive concretisation, destruction of water bodies and forested urban patches, and disregard for surface reflectivity, we have engineered environments that capture and retain heat. This Urban Heat Island (UHI) effect is no longer merely an environmental concern; it is a structural barrier threatening to melt the potential of our rising economy.
The problem lies in the ‘skin’ of our cities. Asphalt roads, dark concrete rooftops, and glass facades have low albedo--they absorb solar radiation rather than reflecting it. A recent study comparing Lodha Palava, a planned township in Thane with an adjacent informal settlement found that the temperature gap between a green-buffered zone and a dense concrete-heavy neighbourhood can reach 2°C to 4°C.

This gap is structural. In unplanned neighbourhoods, narrow streets and urban canyons trap heat, preventing night-time cooling. The lack of a Sky View Factor--openness to the sky that allows heat to escape--turns these areas into thermal batteries.

Our primary response to this rising mercury has been individualistic: reliance on air conditioning.

For affluent classes, AC is a non-negotiable shield. But this creates a stark divide. While private interiors are cooled, public exteriors remain exposed. Thermal comfort has effectively been privatised, while thermal stressis left to those who cannot opt out: delivery workers, street vendors, and factory and construction workers. Environmental risk, much like financial risk, is increasingly stratified — with the thermal tax falling disproportionately on those who cannot opt out.

But this divide is not just a moral issue; it is a financial liability. Heat is a silent productivity killer that threatens the very engine of growth we are banking on, undercutting our national ambition to raise per capita GDP from approximately $ 3,000 to $ 15,000 in the coming decades.

Physiology dictates economics. Beyond a certain wet-bulb temperature, cognitive function slows and physical capacity plummets. For an economy like India’s, dependent on informal and outdoor labour, this is catastrophic. When a delivery rider faces heat exhaustion or a construction site becomes too hot to progress efficiently, the economic engine slows.

We are effectively paying a thermal tax on GDP. The International Labour Organization already projects massive losses in working hours due to heat stress.

The opportunity is that the solutions are low-tech, affordable, and readily available. We do not need futuristic technology; we need better surfaces and smarter planning.

The cool roof revolution: The most immediate solution is the “cool roof” — coating surfaces with high-reflectivity materials. Pilots in a large-scale planned township in the Mumbai Metropolitan Region, as well as in Chennai and Hyderabad, have shown that reflective tiles and coatings can reduce roof surface temperatures by 9°C to 12°C and lower indoor temperatures by up to 2°C. Yet adoption remains low. To bridge this gap, we must prioritise demonstration projects and implement policies that mandate cool roofs for public and private buildings.

Zoning for airflow: Urban planning must move beyond built square feet efficiency and design for “thermal porosity.” Streets should catch breezes, green buffers must act as “cool sinks,” and high-rise clusters should not block wind channels.

Permeable surfaces: We must stop sealing every inch of ground with concrete. Permeable paving allows the ground to breathe and reduces surface heat buildup. Greenery and protected water bodies should be interspersed naturally into the urban fabric.

Public transport: Expanding metro and suburban rail networks is a critical heat-mitigation strategy. By shifting commuters away from private vehicles, cities reduce “anthropogenic waste heat” while supporting walkable urban cores.

Heat shelters: Cities must prioritise public heat shelters that provide outdoor workers with shade, hydration, and medical support, directly protecting India’s economic engine from the “thermal tax.”

Treating urban heat as a lifestyle inconvenience is a strategic error. Whether through the white-washing of roofs or preserving green cover, we must redesign our cities to reflect heat rather than absorb it.

India has the opportunity to pioneer a model of heat-resilient growth for the Global South. A resilient economy requires a liveable temperature; we must prove we can rise without burning out.

(The views expressed are personal)

This article is authored by Aun Abdullah, programme director, Sustainable Urbanisation, Lodha Foundation.