Why is Delhi’s air polluted again? TERI DG speaks about solutions

After a brief respite, Delhi’s air quality has worsened, plummeting into the ‘severe’ quality. As a result, the strictest air pollution control rules are back in place, which include a ban on construction, restrictions on certain vehicles, and schools being held in hybrid format.

While the current spike in pollution levels is attributed to meteorological factors, what makes Delhi especially vulnerable? Which are the biggest polluters? And, what are the possible solutions? Dr Vibha Dhawan, director-general of Delhi-based The Energy and Resources Institute (TERI), which has worked on the issue, explains.

Edited excerpts:

TERI’s 2021 emission inventory highlighted how it’s not stubble burning but transportation is the main culprit for air pollution in Delhi, and construction in the NCR region. Have the main sources of pollution changed over these years?

They are more or less the same. Delhi is a unique city, and with the onset of winter every year, we start blaming stubble burning, which contributes a very small part to the overall air pollution. There are other factors, too, such as the city being air-locked, and when the pollution drops and the wind gets calm, the pollutants get trapped. Stubble burning is a culprit, but only for a few days.

Vehicles and construction activities are the bigger problems. Look at the number of vehicles on the roads, which results in traffic jams. For example, in our apportionment study, we found that in Dhaula Kuan, while the infrastructure is good, there’s the issue of traffic jams, which causes a rise in air pollution. Although we are shifting to electric vehicles, the number of vehicles running on petrol remains high. And while we have metros, there is a lack of last-mile connectivity, which at times, makes it expensive to commute through it.

Then look at construction. While there is a ban on it right now, the building material is often lying around, which flows in the air.

Dr Vibha Dhawan, DG of TERI

Are the rules in place under Graded Response Action Plan (GRAP) – IV enough, or do you see any gaps?

The situation would have worsened if those regulations weren’t in place. However, what is required is a holistic approach, looking at air pollution not alone but in tandem with issues like transportation and construction.

What can be some short-term and long-term solutions?

One of the best short-term solutions is sprinkling water on the road so that the pollutants settle. Having said that, there’s a need to improve the public transportation system. We also have to come up with innovative ideas, such as how some countries put a tax if you are driving alone. We also need to look at how soon we can make the shift to electric vehicles. 

We also need to bring in regulations for construction, such as how to manage building materials, such that it doesn’t get into the air. We also need to see if we’re handling our waste properly, as it, too, contributes to the issue. 

There’s a need to plant more trees, too, something like China’s Green Wall. Also, what’s also required is awareness and an attitudinal change. And for that, there must be certain regulations, not as strict as those under GRAP-IV, that one needs to follow throughout the year. Every small act makes a difference.

Also, every city and place within a city is different. Hence, research is needed to come up with appropriate solutions. For example, we have studied pollution through different months, to understand what are the polluters, and characterised them. So depending on that, once you have that data, then you can develop strategies to control it.

Are the sources of pollution localised and so should be the solution?

It’s partially correct. But the larger policies must come from the Centre. But, they need to be adopted by states as per their individual needs. So it's not one shoe fits all but we all have to wear a shoe.