India: Transforming Delhi from ‘gas chamber’ to healthy city

November 7, 2019
Smog in Delhi. Photo: Ville Miettinen/Flickr.

A few days after Diwali, Delhiites woke up to find the city enveloped by thick smoke and haze, forcing authorities to declare a health emergency.

Air pollution in Delhi and adjoining areas of the national capital peaked at 20 times the permissible level of PM2.5 (a measure of airborne particles with a diameter of less than 2.5 microns).

Air quality fell to disturbingly hazardous levels, remaining at 900–1200 PM2.5 (the permissible level is 100).

Today, Delhi has one of the worst levels of air quality and stands as a primary offender among the world’s cities in terms of air pollution.

Delhi’s administration declared a school holiday, imposed car rationing on the roads and a few dozen flights were diverted from landing at Indira Gandhi International Airport.

The smog comprises a toxic mix of carbon monoxide, nitrous oxides and sulphur dioxide. It also contains particulate matter in smoke emitted from burning agricultural fields, vehicle exhaust, coal-based thermal power plants, dust from construction sites and burning garbage.

There is little variation between the air quality index in Delhi and the 29 other cities in northern India.

Delhi’s air is so hazardous that doctors issued a health warning, asking people to remain indoors and avoid excessive physical activity.

To protect themselves from respiratory complications, people started panic-buying masks. Schools were closed for five days. Throughout this environmental and health emergency, both state and central governments sat mutely watching, trading barbs and shifting responsibility onto each other.

Only on day five, following the Supreme Court’s direction, did they swing into action to take measures to bring the situation back to normal.

The massive toxic cloud enveloping Delhi is the result of a lack of scientific understanding and official policy to mitigate the looming threat of global warming associated with the destruction of natural resources.

It has been known for a long time that burning crop residues after the wheat paddy harvest in the northern states significantly contributes (from 35–65%) to poor air quality in large parts of the Indo-Gangetic [northern fertile] region.

Uncontrolled deforestation in the north-western Himalayas — “nature’s lungs” — has significantly compounded the problem.

Add to this the hundreds of thousands of vehicles entering Delhi every day from neighbouring states — tripling the number of cars in the capital and virtually tripling the belching of toxic pollutants into the air.

Farmers burn the paddy straw in the fields to make space for sowing the wheat crop. They have a small window of two weeks to prepare the land so that the wheat is harvested by March, before the onset of the hot summer.

Any delay or late harvesting in the hot March temperatures imposes a huge yield penalty. Hence, farmers opt for residual stubble burning — a quick recipe to clear land and make ready for the early November wheat sowing.

Indian soils are poor in organic carbon (humus levels hover around 0.1–0.3%, against the recommended 3%) and badly require incorporation of the straw back into the soil to retain soil health and reduce total dependence on chemical fertilisers.

As time is short, farmers cannot wait a few weeks to let the crop residues decompose and fertilise the soil. Farmers already complain of unprofitable cultivation, due to high costs of fertilisers and seeds coupled with low profit margins. They are not ready to bare extra expenditure on incorporating the stubble, paying high costs for farm machines and diesel oil.

In a field experiment organised by the Norman Borlaug research farm, near the Punjab Agricultural University, scientists in Ludhiana developed a “Happy Seeder” — a machine that sows the wheat seed in between the harvested paddy stubbles, avoiding tillage. (Borlaug was a significant figure in India’s Green Revolution.)

This low tillage sowing in the left-over paddy or maize straw incorporates the straw back in to soil, thus enriching its fertility.

This technology has been demonstrated successfully for the last three years and has reduced the application of fertilizers, resulting in a 10% higher yield for the subsequent wheat crop.

Nearly 500 million tons of paddy straw is produced nationally each year. Nearly 80% of the straw from Punjab, Rajasthan and Haryana is burnt in the fields soon after harvest, also depriving its use as cattle feed.

Ploughing the straw back into fields improves the level of organic nutrients. It can also be used for electricity, ethanol and natural biogas production as well as in cardboard manufacturing.

The Indian Council for Agricultural Research (ICAR) recently developed microbial capsules that decompose leftover paddy straw in the fields.

Similarly, technologies for natural gas and electricity production from crop residues have been demonstrated in viable small-scale levels in rural areas by institutes of technology in Chennai, Khargapur and New Delhi.

What is needed is the immediate initiation of pilot projects to scale up these indigenously devised technologies and popularise them among farming communities by offering attractive subsidies.

Better utilisation of biomass for the production of compost has already been successfully demonstrated in Rajasthan. Such measures will develop rural small-scale industries, bring extra income and employment to crisis-ridden farmers and reduce environmental pollution.

The present mode of mass commodity production has plundered natural resources and broken the existing ecological equilibrium in nature.

In the late 1850s Karl Marx, citing the depletion of soil fertility and pollution of soils and rivers in England, commented that capitalism, with its sole intention to make profit, plunders natural resources and alienates labour from nature. This was later described as “metabolic rift” by environmental Marxist John Bellamy Foster.

Marx recognised the need to keep nature safe so that it could be passed on to future generations.

To return Delhi’s air from a “gas chamber” to air fit for both environmental and human health requires governments to identify measures, such as the easy availability of cheap and subsidised farm machinery, rejuvenating farm advisory systems, implementing conservation agriculture, biomass treatment for the production of ethanol and electricity and the manufacture of packaging material.

Such measures can be undertaken in villages as small-scale pilot projects, involving rural youth to make farming profitable to small farmers and to restore the environment.

[Dr Soma Marla is the principal scientist at the Indian Council of Agricultural Research — National Bureau of Plant Genetic Resources in New Delhi.]

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