How can Delhi finally end chronic air pollution?

This week, the air quality index (AQI) in India's capital is hovering at "unhealthy" levels between 200 and 300. The index indicates the measured concentration of pollutants like fine particles in the air at any given time. Still, locals could breathe a sigh of relief because the AQI of over 1,700 was measured in some parts of the city last week. Those values were among the highest levels ever recorded.

The Delhi National Capital region is no different than other Indian cities, with factories, coal-fired power plants, diesel generators, vehicles, construction and wood fire contributing to poor air quality.

However, seasonal crop-burning fires in neighboring states of Punjab and Haryana add to Delhi's air pollution. The practice of burning hay and stubble helps farmers clear their fields, but it also increases the risk to the city. New Delhi's geography in the low-lying Indo-Gangetic plain also puts it at a disadvantage. Unlike Mumbai, which lies by the ocean, Delhi's stable wind conditions trap pollutants instead of dispersing them. 

Despite this, there is still hope for India's capital. There is expert consensus that political will to enact policies addressing chronic air pollution can make Delhi breathable again.

Managing Delhi's airshed

Air pollution crosses regional, political, and national boundaries. Managing the airshed, which is defined by the World Bank as a "common geographic area where pollutants mix and create similar air quality for everyone," becomes crucial.

Delhi's airshed also includes both Indian and Pakistani Punjab, part of Rajasthan, Chandigarh and Uttar Pradesh.  

"Airshed management would mean combining the data sets of polluting factors with meteorology conditions for the next three to five days and restricting their operation," said Sunil Dahiya, founder of Envirocatalysts, a New Delhi-based clean air advocacy group.

"In the long-term, we either have to shift to cleaner fuels or have more efficient pollution control technologies," he told DW. 

Curbing crop stubble burning

Seasonal agricultural stubble burning is one of the major pollutants across this region in early winter, contributing up to 16% of polluting factors this year. Mitigating air pollution caused by stubble burning would require cross-governmental coordination in this airshed region.

Burning the remains of crops is an easy way for farmers to clear their fields, but it is a primary source of air pollution.

Ashish Sharma, air quality program manager at the WRI India Ross Center for Sustainable Cities, said that imposing and implementing fines is one approach to mitigate stubble burning, but added more holistic methods can have a long-term impact.

"Providing incentives for farmers to adopt sustainable practices, such as bio-decomposers and residue management equipment like happy seeders, is essential," he told DW.  A happy seeder is a device that allows crops to be seeded in the residue of previous crops.

"While policies are in place, more robust implementation and better support mechanisms are needed to scale these solutions," added Sharma, who is also the founding CEO of Sustainability Alternatives UK, a sustainability consulting startup.

"Accurate data verification is critical to ensure satellite observations accurately reflect actual stubble burning incidents," he said.

"Implementing appropriate ground-level checks will ensure more accurate quantification of stubble burning, enabling more effective policy action," he added.

Controlling emissions

The Delhi capital region and its surrounding area are home to auto, chemical, plastic and other factories that emit pollutants into the air. 

"It is literally a crime to allow any big polluting industry to come up in this region until we shift to cleaner fuel or reduce emissions," Dahiya said. 

"We are at a stage where we don't even talk about the absolute emission load coming from different sectors such as transportation, power, industry, waste, and construction. We cannot control meteorology; we have to start reducing the emission load," he added.

Better public transport 

New Delhi has a strong metro rail system, but its connectivity still leaves many gaps. The population is also reliant on buses, and the city aspires to eventually electrify 80% of its bus fleet. Many rickshaws have already switched from diesel to liquefied petroleum gas (LPG).

Even so, this has not been effective in reducing the number of private vehicles on the roads. 

With a population of 33,807,000 as of 2023, according to government data, new residential buildings and high rises are continually being built in New Delhi, especially in suburbs and surrounding areas.  

"We need to come up with integrating different transport modes and making it affordable for everyone. If people start shifting from private to public modes of transport, the existing systems will not be able to handle the crowds. We need to invest heavily in upgrading the pre-existing public transport systems,” Dahiya said. 

"We need to provide better infrastructure for people to walk and cycle on," he added. Most parts of New Delhi have no bike paths or usable pedestrian sidewalks. 

Waste management 

An expanding city with a rapidly increasing population means extra waste generation.

Delhi generates 11,342 tons of waste daily, according to an estimate by the Municipal Corporation of Delhi (MCD). But only a part of it gets processed or recycled. This leaves the rest of the city's waste rotting in landfills and contributing to environmental pollution. 

"There are certain pockets which segregate their waste and even compost on site, but this needs to happen at a larger scale," Dahiya said.

Pollution gets caught up in politics

Measures to improve Delhi's air quality are often mired in a tussle between the central and state governments, with both sides trying to shift blame for the chronic pollution. This makes it hard to build political will and coordinate policy between stakeholders.

The problem extends even to obtaining reliable air quality measures. India's measurement scales are considered to be more lenient than WHO standards. 

"Local governments often face challenges in reporting air quality data comprehensively, sometimes due to concerns about reputational risks or funding implications," said Sharma.

He told DW that transparent and precise data collection is "essential for driving actionable solutions and engaging the public effectively," he added.

"While metro cities like Delhi have relatively strong monitoring systems, smaller cities in northern India urgently need more attention. Many monitoring stations are either dysfunctional or lack quality control, which undermines efforts to draw meaningful insights" to meet air quality standards.

The road ahead 

Recently, China's capital, Beijing, and Delhi both featured among the most polluted cities in the world.

Delhi remains at the top of this list, but Beijing has managed to drastically reduce its pollution levels with stronger budget allocation and a push towards renewable energy. 

Tackling emissions control, urban planning, political cooperation might seem like a daunting task. But Delhi has several examples of cities it can take inspiration from. 

"Around the 1950s, cities like London and Los Angeles were grappling with severe air pollution crises that mirrored what Delhi is experiencing today. What enabled these cities to make significant progress?" Sharma asked.

"It wasn't one quick fix, but a series of stringent policies, technological innovations, and long-term strategies. London shifted away from coal-based energy production and reduced emissions from high-pollution industries. In Los Angeles, the focus was on overhauling transportation," he added.

"While much can be learned from international examples, India has already made significant progress," said Sharma, citing examples such as the Graded Response Action Plan (GRAP), which is a set of emergency measures implemented to prevent further air pollution when Delhi's AQI hits a high threshold.

Edited by: Wesley Rahn