In one of the worst episodes of severe air quality this season, a thick blanket of haze hung over Delhi since Monday night and shrouded the city for at least four days, with some experts also comparing it to ‘The Great Smog of London, 1952’.

Anumita Roychowdhury, executive director, Centre for Science and Environment (CSE), talks to Shagun Kapil about the alarming levels of air pollution in the national capital and what can be done to prevent another such episode.

What should we call the thick haze that has covered Delhi-NCR since Monday night? There is divided opinion whether this is smog.
Scientists tell us that in the last three days Delhi and NCR have experienced very calm and still conditions with no wind to blow away the pollution. Simultaneously, two air circulatory systems in the region — one from the west bringing pollutants from farm fires and the second from the east bringing more moisture further trapped pollution at the ground-level creating the deadly smog.

What are the major pollutants in it? What is the difference between fog and smog?
This is different from fog that we see in the hills. Fog means white low-hanging clouds with condensed moisture. What you see in Delhi-NCR is a little fog mixed with pollutants and dust that remains suspended in the air and creates a blanket of toxins.

Is smog and deteriorating air quality a non-issue? Aren’t the government and people realising its ill-effects?
It is over simplistic to say that no one understands or cares. I think there is a lot more popular conversation and outcry around killer air today than ever before. No other city has seen so many news headlines on air pollution as Delhi has. Air pollution is not a new battle. Yet this city has witnessed denial whenever action has been pushed. Each and every action, including CNG programme, improvement in emissions standards, sanction on dirty industrial fuels, parking policy and many more have faced serious backlash because of resistance from lobbies. This has delayed hard and comprehensive action.

We saw a similar smog episode last year. And the moment winter is over its back to business as usual. There have been some measures like introduction of Graded Responsibility Action Plan (GRAP). But is the government doing enough to enforce long-term measures to control air pollution?
We need a deeper understanding of what is going on in the city. After Delhi gained from its initial phase of reforms that involved shifting of polluting industries, closure of coal power plants, implementation of CNG programme for public transport and improvement in emissions standards for vehicles, it lost momentum. The lull period that followed saw an overwhelming increase in sources of pollution, including vehicles, construction activities and waste burning, which overwhelmed all efforts. The deadly Diwali smog last year triggered second phase of reforms. Even though the action so far is too little, the GRAP presents an opportunity to catalyse long-term action.

Let us be clear Delhi-NCR has to reduce particulate pollution by as much as 74 per cent to meet the clean air standards. It cannot be achieved with small incremental steps. There are limits to what GRAP can do if more comprehensive systemic action is not put in place.

For example, restraint on cars under GRAP is challenging without efficient public transport system. Penalty on garbage burning without providing an efficient solid waste management system cannot work. Farmers will continue to burn crop residues if solutions like mulching and power generation are not scaled up.

The need is to devise long-term plans. Yet no one is talking about the urgent implementation of comprehensive action plan for long-term action on all sources of pollution that the Supreme Court has just approved. This city must not let this chance go.

Can you give examples from other countries that have been successful in dealing with air quality?
Several countries have successfully prevented early deaths and improved average life expectancy at birth by taking various stringent steps. The lesson from others is the level of stringency they adopt to leap ahead, and not get lost in small steps.

Beijing while massively scaling up its public transport has also capped the number of cars that can be sold; does not allow older cars to enter city centre and has banned diesel cars. London has imposed congestion as well as emissions charges to make entry into central London prohibitive. We too need stringent and sustained measures to address the health emergency that has arisen due to increasing air pollution.