India’s winter air turns toxic: UNEP warns crisis is ‘nearing disaster levels’

A pale, opaque haze has once again settled over north India. For millions in Delhi and nearby regions, winter has become a season of masks, burning throats, stinging eyes, and a growing fear that even breathing may be harming their health.

“This is no longer just an environmental issue. We are breathing ourselves to death,” says Dr. Balakrishna Pisupati, Head of the United Nations Environment Programme (UNEP) in India. “An Air Quality Index (AQI) of 400 or 500 is 35 times higher than international safe limits. That is air in the severe category — dangerous for everyone.”

Across India’s northern plains, these numbers have become unsettlingly familiar. But the science behind the haze tells a deeper story.

The winter trap

Every November, as temperatures drop and winds still, the atmosphere transforms. Cold air becomes dense and heavy, refusing to rise. Pollutants — dust, smoke, industrial emissions, vehicle exhaust — get trapped close to the ground like a blanket pulled tight over the city.

“In summer, rising warm air carries pollutants upward. But in winter, the air is dense and barely moves,” explains Dr. Pisupati. “Delhi often sees wind speeds of just 3 or 4 kilometres an hour. That means whatever enters the air stays there.”

Delhi’s geography amplifies this trap. Surrounded partially by the Himalayas, the region around the capital forms a shallow bowl. The pollutants have nowhere to go.

This meteorological cocktail has turned the winter months into a predictable health emergency.

Many sources, not one villain

Much of the public conversation narrows the crisis to a single cause: crop-residue burning in neighbouring states. But UNEP’s assessment paints a broader, more complex picture.

“There is no single culprit,” says Dr. Pisupati. “Construction dust, brick kilns, industries, vehicular emissions, diesel exhaust, crop burning — each of these contributes. What changes in winter is that the dispersion mechanism collapses. Everything accumulates.”

Different pollutants overlap, interact, and settle in the lungs of people living across Delhi National Capital Region (NCR) and beyond. The result is an annual spike in asthma, bronchitis, cardiovascular strain and respiratory infections.

A long road ahead

India has taken notable steps. The Commission for Air Quality Management (CAQM) — a statutory authority — oversees coordination across states. The National Clean Air Programme (NCAP) seeks to reduce particulate pollution. Investments in monitoring networks, forecasting tools, and emergency action plans have increased.

But Dr. Pisupati cautions that even the strongest policies falter without broad cooperation.

“You cannot solve this in two months. Air pollution must be managed all year round, and by all stakeholders — governments, industries, households, commuters, resident welfare groups, and enforcement agencies. Behavioural change is essential.”

Compliance remains uneven. So does public participation.

“We need people to reduce burning, follow advisories, rethink vehicle use, manage waste better, and take responsibility at the community level,” he says. “Without that, even the best policies will fall short.”

Where is India headed? Towards stabilisation or deeper crisis?

The UNEP assessment is blunt.

“Air pollution in India is close to becoming a disaster,” says Dr. Pisupati. “Its effects are not limited to a season. Pollutants that enter the body now stay much longer.”

The solution, he argues, rests on three pillars:

1. Policy coherence across ministries

You cannot subsidise polluting activities in one sector while trying to reduce emissions in another.

2. Cross-state cooperation

Air does not recognise borders. Regional coordination is essential.

3. A multistakeholder, people-centred model

Industries, micro-enterprises, civil society, youth, media, academia, and health professionals must work together.

UNEP has launched an Air Quality Action Forum, a platform where large and small industries, community groups, experts, media, and young people collaborate on solutions — from technology upgrades to clean operations to behaviour change.

Climate, development, and behaviour

India’s climate transition is accelerating. The country is among the largest adopters of renewable energy, surpassing some of its own 2030 goals ahead of schedule. Yet, air pollution persists.

“Policies and investments can take us far, but without behavioural change, we will not succeed,” Dr. Pisupati stresses. “Environment is unique — everyone is impacted by it, and everyone contributes to its problems.”

UNEP and India’s Ministry of Environment are now designing a national-level behaviour change programme aimed at reducing individual environmental footprints.