Had the situation not been so desperate, then the AAP government’s proposal to sprinkle water from helicopters would have been considered hare-brained. But, a more practical solution to tackling air pollution may well be around the corner and it lies in the success of a pilot project in Iceland.

At a geothermal power plant in Iceland, Climeworks, a startup, inaugurated on Oct 11 the first system that does direct air capture and verifiably achieves negative carbon emissions.

Although it’s still at pilot scale—capturing only 50 metric tons CO2 from the air each year, about the same emitted by a single US household or 10 Indian households—it’s the first system to convert the emissions into stone, thus ensuring they don’t escape back into the atmosphere for the next millions of years, said an article in the World Economic Forum. 
So, how does reversible absorption work?

The idea is to run a mixture of gases (air being the prime example) over a material that selectively absorbs CO2. Then, in a separate process, that material is manipulated to pull the CO2 out of it. The separated CO2 can then be compressed and injected underground. Typically there’s a limited supply of the absorbing material, so it will get put through the cycle once again to capture more of the greenhouse gas.

Last year, when the air had become toxic in Delhi, the Aam Aadmi Party (AAP) government formulated a plan to put in place three-tier air treatment system. It included setting up of wind purification units, mist fountains and virtual chimneys at five major traffic intersections.

During Diwali, when pollution worsened further, Times of India reported the government announced a plan to install outdoor air purifiers at five major traffic intersections -- Anand Vihar, ITO, Sarai Kalen Khan, Kashmere Gate and IIT (Delhi) or AIIMS.

This year, AAP government sought permission from the Centre to sprinkle water from choppers and it was ready to bear the expenses.

In some select areas, fire brigade sprinklers were put to use to help improve the air quality. Fire tenders from 50 of Delhi’s 53 fire stations sprinkled water to settle the dust.

All these clearly are knee-jerk reactions which cannot be sustained on the long run. Once a system that is being developed by Climeworks can be scaled up, then it can be put to use in Delhi.

Perhaps what is needed is to encourage innovation and ask technologists to develop similar reversible absorption systems. An out-of-the-box solution may well come from the students of IITs and other engineering colleges.

Indigenous technology would not only be a lot cheaper, it will be much easier to maintain, specially since it would be built by material that has been locally sourced. By using those systems, the ambient air quality of the national capital can be considerably improved.