Clouds of smog looming over our heads and enveloping vast tracts of the city in the past few days turned Delhi into the most polluted city in the world and a veritable gas chamber, with PM 10 levels touching an alarming 999 on November 8 on the World Air Quality Index. As Delhi state Chief Minister Arvind Kejriwal reintroduced the odd-even car rationing system, the debate on air pollution has again assumed center-stage in the public discourse and a spate of blame-game, accusations and counter-accusations have just begun.
High-resolution earth observation images show stubble burning
While the Delhi-NCR region does have an issue with loose dust due to heavy construction activities, vehicular pollution and unregulated factories belching out smoke — all contributing to make the region one of the most polluted in the world — however, satellite imagery released by NASA very clearly establishes stubble burning in the agrarian belts of Punjab and Haryana as the main reason behind the drastic spike in pollution levels this time.
The set of images released by NASA’s EOSDIS Worldview platform — which allows a user to interactively browse global satellite imagery within hours of it being acquired — throws light on stubble burning trends and patterns. The data shows that crop burning intensified in the latter half of October, and was mainly concentrated in the Punjab.
Why does it become so severe this time of the year?
Stubble – or the left-over agrarian waste – is burnt by the farmers of Punjab and Haryana after the harvesting is done. Burying the waste or vermicomposting it to make manure – as is done by farmers in many areas of Uttar Pradesh – is undoubtedly environmentally friendly and a better option, but it is also time-consuming and requires arduous labor. With crop rotation and two harvesting seasons a year nowadays, farmers have to clear the waste within a period of just 15 days, so they look for the most cost-effective method which also has the benefit of being least time-consuming.
Since mid-October 2017, smoke from crop fires in Punjab and Haryana is blowing across northern India and Pakistan. With the coming of cooler weather in November, the smoke mixes with fog, dust, and industrial pollution to form a particularly thick haze. A lack of wind, which usually helps disperse air pollution, further compounds the problem for several days in November.
The above image, a data map based on observations from the same sensor portrays aerosol optical depth, which is a measure of how airborne particles affect the reflection and absorption of light by the atmosphere. Red-brown colors indicate skies thick with aerosol pollution. Many big cities—including Lahore, New Delhi, Lucknow, and Kanpur— face increased levels of pollution.
As seen in the third image, which was captured by Terra, thick haze continued to linger over the region on November 8, 2017.
What is to be done?
It is an oversimplification to pin the entire onus on farmers and hold them culpable without understanding the complexities at play here or why the farmer prefers burning stubble over other traditional waste disposal methods.
The advent of technology, mechanization of agriculture and introduction of the high-yield variety of seeds has boosted agricultural production, but at the same time, the use of mechanized thrashers and harvesters leave long-standing stems in the field, which has made large-scale incineration almost a necessity.
The way forward over here is to make an outreach to the farmers, raise awareness about the health hazards of stubble burning and incentivize other alternative agrarian waste disposal methods that can also help the farmers earn an extra buck or save on the money for fertilizers.
Technologies like precision farming can go a long way in making practices like stubble burning obsolete and keeping the environment clean.
For instance, when rice is ready to be reaped, a tractor or a harvester would collect the grain; a spreader distributes the straw that remains on the ground and the Happy Seeder drills into the land to seed the wheat. And subsequently, there would be no need to burn.
It would require active planning, coordination, and execution involving both the government and non-governmental organizations in the agrarian sector. But before that, the first step is to acknowledge the acute severity of this problem and not find recourse in negligently condoning it or paying lip service.
Air pollution has become the elephant in the room and nothing short of permanent, concrete steps and a determined will to act upon it with concerted efforts would suffice.