Stubble burning in Punjab has subsided, but the air quality in Delhi continues to be very poor. Who is responsible for air pollution in Delhi?

Major causes

Air pollution in Delhi is not a new phenomenon. Delhi has been facing the problem of air pollution continuously for many years now. When the incidence of stubble burning was very high on November 9, 2023, the data released by the System of Air Quality and Meteorological Forecasting Research (SAFAR-India) showed that the levels of PM10 and PM2.5 particles in the air were 412 and 248 micrograms per cubic metre, above the safe limits of 100 and 60, respectively.

Factors such as excessive bursting of firecrackers during festivals, vehicular emissions, cooking using wood, waste burning, fumes from factories and power plants and excessive construction activities are said to be responsible for such extreme pollution. However, in the last few years, the Delhi government has been saying that the burning of crop waste by farmers in Punjab and Haryana is the main cause of air pollution.

Stubble burning occurs for just a few weeks in October-November (from the last week of October to the second/third week of November), when according to the SAFAR data it could account for 30-40 per cent of the pollution levels on same days. But the high AQI levels persist well beyond this period (Table 1 and Chart 1).

Delhi’s problem

Supporting the observations made by the Supreme Court on November 15, 2021, most studies have underlined that only 20 per cent of the pollution is caused by neighbouring states and the remaining comes from Delhi. An estimate made by SAFAR-India shows that the contribution of stubble burning to Delhi’s PM2.5 was only in the range of 10-20 per cent during the last week of October 2023.

It however, increases, as the data for the current year shows, in November. A recent (2016) joint report by IIT Kanpur and others suggests that Delhi’s air pollution is caused by road dust, smoke emitted by power plants and garbage burning. Why then do we repeatedly blame the farmers?

Crop waste burning is not a new phenomenon in India. Over time, farmers have been setting fire to their fields after harvest to get rid of unwanted plants and bushes quickly, cheaply and easily. The burning of stubble has increased in recent years due to the increased use of mechanised harvesters. As harvesters cannot reach the bottom of the paddy crop, farmers are forced to rapidly burn crop waste to grow Rabi season wheat on time.

For example, in most wheat-growing States, there are only three weeks between Kharif paddy harvesting and wheat sowing in Rabi season. Wheat sowing should be done from the third week of October to the middle of November. If farmers miss it, the yield of the wheat crop will significantly be reduced. Due to this, farmers have been burning crop waste for many years at a low cost.

The pointers

The government should first understand that Delhi is responsible for its air pollution. To reduce air pollution, residents have to change their lifestyles. The Centre and State governments should re-examine the methodology of urban development. That said, some improvement has occurred (Chart 1).

Importantly, research findings on air pollution should be taken into account and action to be taken on a war footing without any compromise. In particular, the State government should give serious attention to measures such as capping the number of vehicles per household, restricting diesel vehicle registration, use of CNG engines for public transport, prompt disposal of old vehicles, regularisation of construction, effective management of garbage, banning smoke-generating activities at all social events.

To reduce the pollution caused by burning crop waste, we need to invent machinery that can harvest paddy and wheat crops without leaving the stubble. Once the paddy is harvested, the State governments should take steps to send its straw as animal fodder to the needy States. Steps are needed to generate electricity through biomass plants using straw. As suggested by the eminent agricultural scientist MS Swaminathan, State governments should also think of establishing paddy bio-parks to get rid of stubble without causing any air pollution. Importantly, Punjab’s government should also find ways to restrict the cultivation of paddy which has increased over 10 times (from 2.85 to 29.28 lakh hectares) between 1966-67 and 2020-21. If these long-term measures are strictly implemented, air pollution in Delhi can be reduced.

The writer is former full-time Member, CACP. Views expressed are personal

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