How To Control Air Pollution

This is a straightforward article to discuss the real issues concerning stubble burning, including its contribution to pollution in Delhi-NCR, and why the solutions promoted by the government are not working.

- Chandra Bhushan

Combine Harvester is the problem as well as the solution for stubble burning

Let’s start with the contribution of stubble burning to air pollution in Delhi-NCR. While we can bicker over the numbers, stubble burning is a short duration, highly polluting activity that significantly impacts air quality in October and November. The equation is simple: The 15-20 million tonnes of paddy stubble burnt in Punjab, Haryana, and western Uttar Pradesh, emit PM2.5 that is 4-5 times the annual PM2.5 emissions from all vehicles plying on Delhi roads. Let me repeat: PM2.5 emitted from stubble burning in just 60 days is 4-5 times what all Delhi vehicles emit in the entire year.

The intensity of emissions from stubble burning, therefore, is so high that even if a small fraction of these reaches Delhi, it would cause the city’s air quality to deteriorate significantly. This is precisely what happens during the stubble burning season. The wind coming from the northwest picks up pollutants from Punjab and Haryana and brings them to Delhi, worsening its already polluted air.

The next question is, why do farmers burn paddy stubble? First of all, not all farmers burn it; only about 25% of the paddy residues are burnt in Haryana, and this number goes up to 50-60% in Punjab. So, why do some farmers put their fields to flames while others don’t? There are three primary factors, apart from a few minor ones, that are driving this practice.