Factors behind ‘poor’ air quality
Air pollution remains a persistent issue in India, with the Delhi-NCR particularly recording some of the worst AQI globally each year. It routinely exceeds the safe level of PM 2.5 (atmospheric particulate matter of diameter of fewer than 2.5 micrometres) and PM 10.
Between 2015 and November 2025, the average annual Air Quality Index (AQI) in Delhi has been 235, exceeding the annual National Clean Air Programme (NCAP) targets, the national standard of 60 µg/m³ and the World Health Organisation (WHO) guideline of 15 µg/m³.
There are multiple reasons behind the ever-deteriorating air quality. Although stubble burning in the Indo-Gangetic Plains has often been identified as a major reason, sources of air pollution differ across seasons. During the summer, construction dust and industrial pollution are among the primary sources of pollution. In winter, vehicular emissions and biomass burning in both Delhi and the Indo-Gangetic Plains intensify the problem.
Why air pollution escalate into public health emergency during winter
The issue escalates into a public health emergency during winter due to a combination of factors like low temperature, high humidity, and increased emissions. A winter temperature inversion further worsens the situation by trapping pollutants near the surface and preventing their dispersion in the atmosphere.
Delhi’s landlocked and basin-like geography also contributes to pollution accumulation, although it is not the main determinant. It needs to be pointed out here that cities like Beijing and Mexico have a similar geographical feature and have faced comparable problems with air pollution, but have managed to improve their air quality.
Despite the severity of the issue, the problem of air pollution in Delhi has largely been treated as an episodic and externally driven governance issue, with reactive interventions – often triggered by judicial pressure – rather than through sustained structural reforms. But this approach appears striking as India has an institutional and legal framework for air pollution control.
India’s air pollution control framework
Air pollution control framework in India comprises the Pollution Control Boards (PCBs) at both the central and state levels, established under the Air (Prevention and Control of Pollution) Act, 1981. The main functions of these boards include:
1. Advising the government on pollution-related matters.
2. Laying down emission standards.
3. Monitoring compliance.
However, PCBs often face challenges like financial constraints and inadequate staffing and resources. A recent report by the Foundation for Responsive Governance (ResGov), on the other hand, flagged persistent delays in fund disbursal, low utilisation and a mismatch between pollution sources and spending priorities, while Delhi and Noida grappled with ‘severe’ air pollution.
In the context of the Delhi-NCR region, the CAQM was established in 2020. It was meant to address air pollution in the National Capital Region and neighbouring areas and ensure effective coordination among various agencies and stakeholders.
Key functions of the body include preparing and implementing air quality management plans, overseeing implementation of measures to reduce air pollution, alongside ensuring better inter-state coordination on the issue.
CAQM’s approach to mitigating pollution under scanner?
However, the agency has been criticised for largely having a reactive approach as it resorts to imposing bans and punitive measures when capital starts choking, particularly during winter. A fragmented approach – the execution of CAQM’s directives rests with state pollution boards, municipal bodies and law-enforcing authorities – has at times undermined effective implementation of pollution control measures.
Against this backdrop, intervention by the Supreme Court, the National Green Tribunal, and the Delhi High Court has played a crucial role in compelling executive action and prompting reforms. It is noted that the implementation of these orders has remained weak and inconsistent.
Beyond statutory prohibitions and regulations, various recent initiatives have been undertaken to curb the menace of air pollution, specifically in Delhi-NCR. For instance, the CAQM has revised the Graded Response Action Plan (GRAP), which is an emergency response mechanism for the region.
Alongside, stricter emission checks have been introduced at toll plazas to restrict the entry of highly polluting vehicles, while the entry of non-Delhi private vehicles below BS-IV standards has been banned. The Delhi government has also enforced the ‘No PUC, No Fuel’ policy and is also working on a carpooling app to reduce pollution caused by vehicular emissions.
While these initiatives show a growing recognition of the seriousness of air pollution, they continue to reflect a predominantly reactive and emergency-driven response rather than a shift towards structural, preventive, and long-term reforms.
Insights from global examples
In this context, India’s approach may be contrasted with that of China. To deal with the issue of air pollution in Beijing, China launched a five-year action plan in 2013, treating air pollution as a systemic governance failure rather than an episodic crisis.
It introduced more stringent emission standards for the industrial sector, established incentive and restraint mechanisms such as carbon trading and environmental taxes, promoted clean energy in residential sectors by replacing coal-based heating with natural gas or electricity, and imposed driving restrictions, etc. A special emphasis was placed on reducing PM2.5 concentrations.
Another example could be London’s great smog of 1952, which offers a powerful comparative lens. The crisis was addressed through political and regulatory interventions, culminating in the enactment of the Clean Air Act in 1956. This marked a shift by banning high sulphur coal, transitioning to cleaner fuel, relocating polluting industries, and restructuring the city’s transportation system.
Role of green belts and ecological buffers
Apart from regulatory measures, green belts and ecological buffers, such as the Aravalli range and urban green spaces, constitute a foundation for air pollution mitigation and environmental sustainability, especially in densely populated regions like Delhi-NCR.
The Aravalli, one of the oldest mountain ranges in the world, holds immense ecological significance for the region. It acts as a natural barrier against dust-laden winds in the region. It also maintains ecological balance by regulating temperature, maintaining groundwater recharge, and preventing land degradation and desertification in north-western India.
Similarly, urban green spaces such as city forests, parks, green corridors, and roadside plantations play a vital role in air quality management. Green spaces can significantly reduce PM10 concentrations. Vegetation absorbs pollutants like nitrogen dioxide, sulphur dioxide, and particulate matter, while also reducing the urban heat island effect, which traps pollutants near the surface.
Despite their importance, green spaces are often treated merely as aesthetic assets rather than as environmental infrastructure. But the recent controversies around the Aravalli underscore the fragility of these environmental buffers.
Need to shift from reactive approach to long-term, preventive planning
Air pollution in Delhi remains a serious problem throughout the year, but escalates into a public health emergency during the winter. It is clear that the crisis demands a shift from the seasonal, reactive approach to long-term, preventive planning. Global examples demonstrate that clean air can be achieved through sustained political commitment, strong institutional capacity and preventive regulation.
Some of the measures towards achieving this could include:
1. A clear demarcation of institutional responsibilities and accountability.
2. Revitalising Pollution Control Boards with adequate funding and human resources.
3. Channelising underutilised funds allocated under the NCAP towards targeted interventions.
4. Focus on long-term and structural strategy by the CAQM.
Relocating polluting industries outside the region, investing in green and affordable public transportation, and imposing environmental and congestion taxes on private vehicles are among other measures discussed by some experts.
Such regulatory and economic measures may be complemented by creating and protecting natural buffers and green spaces in the region, as well as by sustainable urban planning. However, all these efforts will generate results only if they are supported by strong political and public will, and meaningful behavioural change.
Post read questions
Why does the issue of air pollution in Delhi escalate into a public health emergency during the winter? What are the major factors behind it?
Discuss the limitations of India’s current air pollution control architecture with special reference to the role of Pollution Control Boards (PCBs) and the Commission for Air Quality Management (CAQM).
Discuss the significance of green belts and ecological buffers such as the Aravalli range in urban environmental management.
What structural reforms are needed in India’s air pollution governance framework to move from episodic control to long-term prevention? Illustrate your answer with examples.
(Renuka is a Doctoral researcher at Himachal Pradesh National law university, Shimla.)
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