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Groundwater, the unexpected villain in India’s air pollution crisis

A man rides a rickshaw on a smoggy morning in New Delhi - REUTERS
A man rides a rickshaw on a smoggy morning in New Delhi - REUTERS

Air pollution in India is at crisis point. Killing an estimated one million Indians each year, it is even more deadly than smoking, high blood pressure, or malnutrition.

At the same time, North India is contending with one of the most severe water shortages the country has ever seen, as groundwater has depleted to unprecedented levels.

Yet, two of India’s Northern governments’ well-intentioned attempts to address their water crisis has inadvertently worsened air quality as a result – a potent symbol of how difficult environmental policymaking can be.

In a study by the International Maize and Wheat Improvement Center (CIMMYT), water conservation policies by the regional governments of Haryana and Punjab were revealed to actually aggravate air pollution.

Both governments introduced legislation in 2009 to prohibit early rice establishment in the season, in an attempt to reduce groundwater usage for irrigation. The legislation pushed back rice planting from May, when farmers were solely dependent on groundwater reserves, to June, in order to bring cultivation closer to the monsoon season.

By delaying the rice planting season, farmers had fewer days between harvesting the rice and planting the next crop of mainly wheat, meaning Indian farmers have been forced to burn their residues within a narrower stretch of time. With more of these farmers setting fire to their plant waste together, peak fire intensity increased by 39 per cent, contributing significantly more to atmospheric pollution had it been more spread out.

Known as stubble burning, crop residues, such as roots and stems, are regularly burned to help prepare a field for seeding. Illegal in India, the millions of smallholder farmers in the region still regularly follow this practice despite the harmful chemicals released into the atmosphere.

Burning agricultural waste predominantly releases PM2.5 aerosols, tiny particles that are so small and light that they can be easily inhaled by humans and animals. Studies show that human intake can lead to chronic disease such as asthma, heart attacks, bronchitis and other respiratory problems. Children are also more vulnerable to the effects of air pollution, which can affect their neurodevelopment, lead to stunting and increase the chances of having a cardiovascular disease later in life.

Haryana and Punjab’s proximity to the Himalayas means it is landlocked, largely blocking air pollution from escaping to the north which creates a valley effect. Seasons affect this further, particularly winter, in which all factors converge to create peak pollution. The effect is that contributors to air pollution are felt more heavily in the region.

So, while groundwater policies appear to be halting water depletion, they have had the inadvertent effect of worsening air pollution, the country’s silent killer.

And with Indian citizens subject to air that is at least ten times over the World Health Organization’s safe limit, and home to thirteen of the world’s top twenty cities with the highest levels of air pollution, addressing pollution has never been more important.

India’s air quality has deteriorated to such an extent that levels of pollution now exceed those of neighbouring China, where air quality has been a notorious problem for the past two decades.  The Chinese government, however, introduced legislation in 2013, which has abated air pollution and even achieved record reductions.

For the Indian government, there is still a path to clearer skies and safer water practices if they treat both issues as interconnected and take action accordingly. Groundwater, air quality, economics and technology all impact one another.

The current policy environment in India actively encourages the prioritisation of water-intensive crops like cereals, which produce high levels of residue. The government should instead promote rice varieties that either take less time to grow or are less water-intensive, promote irrigation water saving technologies or less water demanding crops such as maize. This could help alleviate groundwater losses whilst reducing the damaging concentration of agricultural burning.

Another sensible approach would be embracing technologies that provide farmers the means to avoid stubble burning. Happy Seeder, for instance, is a drill that plants seeds by clearing the loose straw that would usually get burned by farmers, ruling out the need to burn residues. Financial incentives may provide the additional boost needed to encourage farmers to adopt these solutions.

After all, complex problems will not be solved with simple solutions especially when it comes to air and water, two of the world’s most precious resources.

  • Balwinder Singh is the cropping systems simulation modeler at the International Maize and Wheat Improvement Center (CIMMYT)

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