Every winter, Delhi’s air pollution returns to the centre of India’s public debate. Emergency restrictions are announced, construction activities come under scrutiny, vehicles face additional curbs, and agricultural stubble burning becomes a subject of intense political and public discussion. Yet, as winter passes, the underlying problem remains largely unresolved.
This recurring cycle raises an important question: if stubble burning is the principal explanation offered for Delhi’s winter smog, why does the city continue to experience dangerously polluted air even when farm fires decline and the agricultural burning season is over?
The answer lies in a fundamental misunderstanding of the problem. India’s air pollution crisis is not merely seasonal. Winter makes it more visible, but the emissions responsible for poor air quality accumulate throughout the year. Addressing the crisis therefore requires a shift from seasonal emergency management to sustained, nationwide pollution prevention.
Beyond the stubble-burning debate
The decline in agricultural fires demonstrates that targeted interventions can produce results. Punjab recorded 5,114 farm fires in 2025, a reduction of approximately 93 per cent compared with 2021. Yet Delhi’s annual average PM2.5 concentration remained around 96 micrograms per cubic metre in 2025, more than twice India’s annual standard of 40 micrograms per cubic metre.
The lesson is clear: reducing stubble burning is essential, but it cannot independently deliver clean air.
According to the source-apportionment findings cited in the Centre of Sustainability for Pure Earth’s policy paper, secondary aerosols and transport account for substantial shares of Delhi’s winter PM2.5 pollution. Secondary aerosols are fine particles formed in the atmosphere when gases released by vehicles, industries and combustion processes react with other substances. These particles can travel considerable distances, making air pollution a regional challenge rather than a problem confined to municipal boundaries.
Delhi’s pollution also reflects emissions from outside the capital. Estimates cited in the policy paper indicate that roughly two-thirds of the city’s winter PM2.5 burden originates beyond its administrative boundaries. A city cannot solve a problem whose sources extend across multiple districts and states through local restrictions alone.
The debate must therefore move beyond assigning blame to individual sectors or regions. India needs a comprehensive strategy that addresses agricultural burning alongside transport emissions, industrial pollution, coal combustion, construction dust, waste burning and the gases that contribute to secondary particle formation.
Air pollution does not respect state boundaries
India’s air quality challenge extends well beyond Delhi and the Indo-Gangetic Plain. Satellite assessments cited in the CSPE paper indicate that 447 of India’s 749 districts exceed the annual PM2.5 standard. Emerging pollution hotspots include industrial and mining belts in eastern India, parts of the Northeast, Maharashtra’s urban-industrial corridors and areas across the Himalayan region.
These developments should serve as an early warning. If pollution prevention remains concentrated in a limited number of cities, other regions could face increasingly severe air quality challenges as industrialisation, urbanisation, energy demand and motorisation accelerate.
The appropriate unit of governance is therefore not just the city or the state, but the airshed, the geographical region within which air pollutants and their precursors move and interact.
India already has a foundation to build upon. The Commission for Air Quality Management has adopted an airshed-based approach for the National Capital Region. The next step should be to extend this approach nationally through coordinated targets, shared monitoring systems and clear accountability among the states that contribute to and experience the same pollution burden.
Such a framework would strengthen cooperative federalism. States would retain their enforcement responsibilities, while regional mechanisms would help coordinate action, establish common objectives and direct resources towards measurable reductions in pollution.
From emergency restrictions to predictive prevention
India’s response to air pollution has too often been reactive. Restrictions are intensified after air quality deteriorates, even though many of the emissions contributing to the crisis are predictable and persist throughout the year.
Emergency measures have a role, particularly during severe pollution episodes. However, they cannot substitute for structural reforms.
A more effective approach would integrate weather forecasting, pollution modelling and emissions data into a year-round prevention protocol. When forecasts indicate conditions conducive to pollution accumulation, authorities could initiate appropriate measures before concentrations rise sharply.
This must be accompanied by continuous action to reduce emissions from vehicles, industrial units, power generation, construction and waste management. Policies should focus not only on visible smoke and particulate matter but also on precursor gases such as sulphur dioxide, nitrogen oxides and ammonia, which contribute to the formation of fine particles in the atmosphere.
India should also strengthen the National Clean Air Programme by placing greater emphasis on PM2.5 concentrations and precursor emissions, expanding coverage to chronically polluted towns and periodically updating priorities using reliable monitoring and satellite data.
The objective must be to prevent pollution from building up, rather than repeatedly managing its consequences.
Turning agricultural residue into an economic opportunity
The transition away from crop-residue burning also presents an opportunity to strengthen rural livelihoods and India’s clean-energy ecosystem.
According to the National Biomass Atlas figures cited in the CSPE policy paper, India has approximately 228.5 million tonnes of surplus crop residue annually. This resource could support biomass pellets, compressed biogas and other energy applications, provided that collection, processing, transportation and market access are economically viable.
Coal-fired power plants offer a potential source of sustained demand through biomass co-firing. However, the policy paper highlights a significant gap between the estimated annual biomass requirement for five per cent co-firing across the relevant coal capacity, approximately 38.55 million tonnes, and reported annual offtake of roughly 2.16 million tonnes in 2025-26.
Bridging this gap will require more than asking farmers not to burn residue. It will require predictable demand, commercially viable pellet prices, reliable procurement, accessible finance and investment in rural processing infrastructure.
A proposed Clean Air Transition Fund could help align these incentives. Existing air-quality grants and other suitable funding mechanisms could be directed towards verified emission reductions, rewarding measurable outcomes rather than expenditure alone. Small and medium enterprises could also receive support to transition towards cleaner industrial heat sources.
In this model, agricultural residue becomes a marketable resource rather than a disposal problem. Farmers gain an additional income opportunity, rural enterprises develop, and energy producers gain access to alternative fuels.
Clean air must become a national movement
Regulation and technology are indispensable, but lasting improvements also depend on everyday behaviour. Open waste burning, poorly maintained vehicles, unnecessary idling, inefficient fertiliser use and unsustainable household and industrial practices all contribute to the wider challenge.
India has demonstrated its capacity to mobilise citizens around large public objectives through initiatives such as Swachh Bharat Abhiyan and Ujjwala. A comparable national clean-air mission could bring together schools, local governments, agricultural institutions, resident welfare associations, industry and community organisations.
Such a mission should promote practical, measurable changes: selling agricultural residue instead of burning it, improving nitrogen-use efficiency, preventing waste burning, maintaining vehicles, strengthening public transport use and ensuring better dust management at construction sites.
These efforts must extend beyond the National Capital Region. Prevention is most effective when it begins before pollution becomes entrenched, including in smaller cities and emerging industrial centres.
A long-term commitment to cleaner air
The economic and human costs of air pollution make inaction increasingly difficult to justify. A study cited in the CSPE paper estimated that air pollution was associated with 1.67 million deaths in India in 2019 and economic losses equivalent to 1.36 per cent of the country’s GDP.
These figures underline why clean air should be treated not simply as an environmental concern, but as a public health, productivity, energy security and economic development priority.
India has the scientific institutions, policy instruments, monitoring capabilities and agricultural resources needed to pursue a more effective approach. What is required now is stronger coordination, sustained implementation and accountability for outcomes.
The way forward is straightforward in principle: govern air pollution at the airshed level, reduce emissions throughout the year, create viable markets for agricultural residue, support industries in adopting cleaner fuels and make clean-air practices a nationwide public priority.
Delhi’s winter smog should no longer be the starting point of India’s response. It should be a reminder of what happens when year-round emissions meet unfavourable weather conditions.
India’s clean-air ambition must extend beyond parali, beyond winter and beyond city boundaries. The goal should not be merely to survive another pollution season, but to build an economy in which cleaner air is a year-round outcome of better policy, better technology and shared responsibility.
Author: Satish Upadhyay, Director General, Centre of Sustainability for Pure Earth (CSPE).
