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Although air quality in New Delhi has improved marginally, NASA images show widespread burning of crop residue over central and south India, indicating higher air pollution across the country

Satellite images released by NASA show widespread crop residue burning in central and south India

The latest report card on New Delhi’s air pollution says that things have visibly improved but there is still a long way to go to achieve clean air. However, extensive burning of crop residue over central and south India is expected to lead to an increase in air pollution across the country.

In its analysis, the Environment Pollution (Prevention and Control) Authority (EPCA) has stated that Delhi and its surrounding region’s air quality is showing slight signs of improvement, but it is still unsafe to breathe yet.

The report that has categorised the national capital region’s (NCR) air quality in the poor to very poor category, a notch better than the severe to severe plus category has come as the winter draws to a close, a season that is marked with meteorological conditions that are adverse for city’s air quality.

Following this EPCA has decided to relax emergency action plan under the GRAP (Graded Response Action Response on Pollution), which means the NCR region can use diesel generators that were earlier banned when the air quality was severe.

The agency has given credit to the collective actions taken by the various state governments, agencies and central ministries for the improved quality and have called it a step in the right direction. “This reduction in pollution levels shows that we can make a difference. But the air is not completely clean yet. We must not lose the momentum in our fight for clean air. We must not lose sight of the fact that right to breathe is fundamental,” said Bhure Lal, EPCA chairperson.

“The air in this region of the national capital is so polluted and toxic that all our combined efforts have reduced pollution merely from the severe-severe plus category to poor-very poor category,” said EPCA member Sunita Narain. “Very poor category is still deadly. According to the health index of the government, prolonged exposure to this level of pollution is hazardous, even for healthy people. This means that all of us breathing this air are exposed to toxins and this will impact our health and more importantly, health of our children. Therefore, we need to do much more to reduce pollution and bring it to the good-moderate level.”

The battle against air pollution needs a comprehensive plan, credible monitoring, enhanced implementation and rigorous enforcement, says the EPCA Report Card.

Air pollution depends on multiple factors, and in the case of Delhi, these range from various sources like vehicle emissions, crop burning in neighbouring states, to ambient dust. Delhi and its surrounding region faces high pollution levels in winter when particulate matters stay trapped close to ground and are unable to disperse out. Both wind speed and direction play a crucial role as they can bring in dust, crop residue burning and moisture.

Crop burning

Crop burning has emerged as one of the major factors in causing air pollution. Massive farm fires in India that take place after every spring and autumn harvest seasons have been a cause of concern for increasing pollution load and carbon dioxide emissions over South Asia.

Extensive burning of crop residue in large parts of central and south India is expected to worsen air quality over India (Image by NASA)

Farmers often burn the crop residue in order to return the nutrients back into fields and to prepare soil for the next sowing season. Due to small time window between two agricultural cycles and lack of finances and technology available to them, farmers often resort to burning crop residue instead of removing and utilizing the residue in a sustainable manner. This in turn releases large amounts of pollutants due to inefficient combustion. The problem gets exacerbated for NCR during winter, when crop burning in neighbouring states of Punjab, Haryana and Uttar Pradesh take place in autumn season.

The latest NASA maps show that that crop burning has started in the central and southern India, which is bound to worsen the air quality of those regions. The map marks the active farm fire sites in red, which are the spots where thermal instruments have recognized temperatures higher than the background.

According to NASA, “Farmers use the method of slash and burn agriculture (setting fires) to rid the overgrown fields of grass and detritus from the last growing season in order to ready the land for a new growing season.  This is a practice that has been going on for centuries in this part of the world.  The area uses this type of field clearing starting in October and going through June with the peak coming in March.”

Agenda for future

In order to check farm fires, a high-level committee setup by the Prime Minister’s Office has drafted a plan for crop burning in states of Haryana and Punjab. The plan has been accepted by EPCA, which has noted that the solution is to provide farmers with alternatives and to educate them that the stubble burning is not in their interest. The National Budget 2018 has allocated INR 12 billion (USD 185 million) to help provide easy subsidy at 50-75% so that machineries used for tilling the residue back into the soil are easily available to the farmers.

According to the 2015 IIT Kanpur study on air pollution in Delhi, the overall contribution of biomass burning to particulate pollution during winter is fairly high — 17% for PM10 and 26% for PM2.5. Already 14 Indian cities are counted among the world’s 30 most polluted cities and unless timely implementation of these actions are not taken, this health issue will only worsen.

Data from the period October 1, 2017 to February 25, 2018 points to a slight improvement in air quality levels. An analysis of the Central Pollution Control Board’s air quality index data shows that the number of days in the severe category has decreased for each month in comparison to the previous year, except in January. In February, 16% of the days were in the moderately poor category, compared to 8 per cent in the previous year.

Also, there is an inverse relation between the PM2.5 concentration and the wind speed and the analysis shows that the overall wind levels and temperature were almost same as the last year, hence the improvement in air quality can be attributed to the impact of GRAP — the emergency actions that were taken to reduce pollution.

Combating air pollution

EPCA has listed out various actions that were taken in 2017-18 in a move towards improving air quality that include Supreme Court’s ban on the sale of BS-III vehicles in India from April last year and advancing supply of BS-VI fuels in Delhi. These are meant to tackle vehicular pollution while for the power plants and industries; there is now a ban on using polluting pet coke in Delhi-NCR region while standards for Sox and Nox (sulphur and nitrogen oxides) have been set up for the first time for the industries to check pollution.

About 600 brick kilns have switched to less polluting zigzag technology and by July this year, only zigzag technology compliant brick kilns will be allowed to operate.


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