Lahore named world’s most polluted city: How much is stubble burning in India to blame

The Pakistan Meteorological Department (PMD) on Tuesday issued an advisory on the rising smog levels. It attributed the present state to industrial pollution and vehicle emissions, saying this would be exacerbated by enabling weather factors that allow harmful pollutants to remain lodged in the atmosphere. The PMD warned that the smog crisis could trigger severe respiratory ailments and lower road visibility, leading to accidents.

For years, the city has regularly featured on the list of the world’s most polluted cities. A handful of factors have worked together to result in the present situation. We explain.

The annual smog crisis

As winter sets in, Lahore and other Pakistani cities are covered in a visible layer of haze that prevents warm air from rising and traps pollutants closer to the ground, in what is called temperature inversion. Lahore in particular is located in a low-lying region surrounded by hills, which traps pollutants and prevents the dispersion of smog.

Stubble burning has often been cited as the major reason for the uptick in smog during the winter months every year. It is typically done to clear the residue of rice crops to pave the way for wheat cultivation. The practice is carried out in Punjab on both sides of the border during the winter months, and both Indian and Pakistani governments have announced punitive measures to discourage the same.

Pakistani politicians have long blamed Indian farmers for engaging in the practice and sending toxic smog across the border. Earlier this month Chief Minister of Punjab in Pakistan, Maryam Nawaz urged for climate diplomacy with India to coordinate their response to the smog crisis.

However, this explains only part of the problem. A study by Pakistani researchers Saima Mohiyuddin, Khan Alam and others published in August acknowledges the role played by vehicular emissions and brick kilns. “The primary sources contributing to elevated PM2.5 concentrations include biomass burning, agricultural residue incineration, vehicular emissions, and industrial activities.” (“Characterization and source identification of PM2.5 during intense haze episodes in an urban environment of Lahore”, Atmospheric Environment: X, Saima Mohiyuddin et al, 2024)

Once known as the City of Gardens, Lahore has faced rampant development over the last two decades, with swathes of land cleared and trees felled to accommodate housing projects and roads. The decline in green spaces across the city compounds the problem, preventing pollutants from dissipating.

Some environmentalists blame the use of low-quality, high-sulphur fuel, and identify coal-fired power plants, such as the 1320MW Sahiwal power plant in Punjab – part of the China-Pakistan Economic Corridor – as the chief polluters.

Tackling the crisis

Cloud seeding when deployed last year enjoyed middling success. The Punjab government used a small Cessna plane to create rain in 10 locations, which witnessed scant rainfall. The effect was immediate, lowering the AQI from the 300s to 189, according to The Guardian. However, these did not prevail beyond a couple of days. Additionally, climate experts have cautioned against relying on the measure owing to its unpredictability. Once rain is induced, it could be difficult to stop it.

Currently, Punjab authorities have reportedly begun a crackdown on smog producers. Pakistani newspaper The Nation reported that over 328 brick kilns were demolished and more than 600 vehicles were impounded for emitting smoke in violation of fuel compliance norms. In 2021, the Punjab government banned the sale of Euro 2 fuel in Lahore to combat vehicular pollution.

Critics view these measures as band-aids in the absence of a cohesive strategy that accounts for urban planning.

Punjab Environment Minister Marriyum Aurangzeb told The Dawn earlier this month that the state was working on a smog mitigation plan which it had set in motion in April. This included the deployment of a smog monitoring unit, bans on single-use plastics and water sprinkling to manage fugitive dust along roads and construction sites.

“This plan incorporates both short and long-term strategies to significantly reduce air pollution across Punjab. This flagship programme aims at tackling pollution at its root through a number of actions like transitioning to greener mass transit, fuel quality inspection, industrial monitoring, tree planting drives, urban forests, drone and thermal technologies for monitoring, Green Punjab and Eco Watch apps and smog helpline”, she said.