Why Permitting ‘Green’ Diwali Crackers in Delhi Defies Logic – and Science

On Wednesday, the Supreme Court permitted Delhi’s residents to burst ‘green’ firecrackers for Diwali from October 18 to 21. A bench of Justices B.R. Gavai (the Chief Justice of India) and K. Vinod Chandran gave this order, but said that the activity would be strictly regulated and limited to specific hours – between 6-7 am and 8-10 pm.

The apex court passed the order after considering the pleas of both the Government of National Capital Territory of Delhi and the Union government to relax the existing ban on the sale and use of firecrackers in Delhi and the national capital region (NCR).

However, the decision to permit green crackers this Diwali in Delhi defies both logic – and science. Here’s why.

First, the science

‘Green’ firecrackers are not really green. They are fireworks and crackers that are manufactured with a reduced shell size, zero ash and a lower raw-material content in compositions, according to the CSIR-National Environmental Engineering Research Institute (NEERI). They emit at least a 30% lesser particulate matter, or a minimum of 20% reduction in particulate matter with at least a 10% reduction in gaseous emissions.

So, while green firecrackers emit fewer pollutants and toxic chemicals (around 30% lesser pollutants when compared to normal firecrackers), they still emit 70% of the pollutants that normal firecrackers do.

Legalising its manufacturing, sale and use is equivalent to effectively legalising heightened emissions during the festive period, said air quality researcher Sunil Dahiya, founder and lead analyst at Envirocatalysts, a Delhi-based research and policy think-tank.

“While each individual green cracker may produce 30% less pollution, this marginal gain will be entirely negated by the sheer volume of firecrackers being burst,” Dahiya told The Wire. “The overall result is expected to be a net increase in emissions, making this a counterproductive measure.”

The only silver lining for air quality is that Diwali falls earlier in October this year, compared to previous years. Meteorological conditions during this period, such as better wind speed, might aid in the dispersion of pollutants, he said.

“Ultimately, it is a ‘wait and watch’ scenario,” Dahiya added. “The critical question is whether the early arrival of Diwali can sufficiently disperse the additional pollution from increased cracker bursting, or if we will break previous records for Diwali-day air pollution. What is clear is that in this balance, public health has been forced to take a back seat.”

Moreover, other solutions that the Delhi government is actively pushing to control air quality – such as cloud-seeding, a technique that hastens condensation of moisture in clouds to create artificial rain – are in no way comparable to the benefits that Delhi’s residents would obtain from eliminating the pollution that their fireworks emit into the air they breathe, experts say.

For instance, though cloud-seeding has been shown to reduce particulate matter levels (PM 10) to some degree, scientists caution that far more studies are necessary to really ascertain this, as well as understand the potential side-effects of cloud-seeding.

Additionally, the Supreme Court’s order that green firecrackers be permitted under strict regulation also depends heavily on the assumption that the Delhi government will actually be able to implement strict regulatory measures in the first place.

Implementation has always been a problem, as air quality modelling scientist Mukesh Khare told Hindustan Times. Khare said that under the guise of green firecrackers, even conventional ones are burst – which again offsets any gains that bursting only green crackers may bring.

Second, the logic

The decision to permit the use of green firecrackers this year for Diwali in Delhi defies logic because the capital city’s poor air days have already begun – even without adding the emissions that Diwali fireworks, green or not, will add to the environment.

On October 14, Delhi’s Air Quality Index (AQI) slipped into the ‘poor’ category with a reading of 201. On the same day, the Delhi government invoked Stage-I of the Graded Response Action Plan (GRAP).

The GRAP is an emergency response mechanism for the Delhi-NCR, and limits certain activities depending on the daily average AQI levels. On October 15 too, Delhi’s overall air quality remained in the ‘poor’ category, with air quality in some locations even dipping to ‘very poor’, The Hindu reported.

Moreover, it is common knowledge that post-Diwali, Delhi’s air quality will worsen. Both changing meteorological conditions (slower wind speeds that ensure that pollutants are not dispersed into the atmosphere) and instances of stubble burning in and around the NCR will contribute to emissions, resulting in poorer air quality.

Delhi’s Air Quality Early Warning System has already warned of this. “Delhi’s air quality is very likely to be in the ‘poor’ category from October 14 till October 16. The outlook for the subsequent six days shows the air quality is likely to be between the ‘poor’ to ‘very poor’ category,” Hindustan Times quoted EWS projections released on Monday as saying.

Per the latest EWS predictions on October 16, Delhi’s AQI at 4 PM on October 15 was 233, well into the ‘poor’ category. It predicts that air quality will be in the same category for the next six days.

It also predicts that AQI on October 20 and 21 – the two main days of Diwali – will shift to the ‘very poor’ category.

The logic, therefore, would be to limit emissions in whichever way possible during these times.

Why SC’s decision raises critical questions

The Supreme Court’s decision to permit the use of green firecrackers this year for Diwali in Delhi raises crucial questions.

First, what has changed now for the apex court to turn around on its earlier approvals and decisions when it came to imposing a blanket firecracker ban?

On October 14, 2024, the Delhi government announced a complete ban on all types of firecrackers until January 1, 2025, to curb air pollution. On November 11, the Supreme Court expressed surprise over the delay in imposing that ban, saying that no religion would promote any activity that contributes to pollution or compromises the health of people.

“The right to live in a pollution-free atmosphere is a fundamental right of every citizen under Article 21 of the Constitution. Prima facie, we are of the view that no religion encourages any activity that creates pollution. If firecrackers are burst in this fashion, it affects the fundamental right to health of citizens,” the top court had said in its order.

In January, the same court extended the firecracker ban till March 2025 in the NCR areas in Uttar Pradesh and Haryana.

Clearly, the Supreme Court had agreed last year that firecrackers were bad for Delhi’s air quality. So what changed, about a year later?

Second, without any change in facts, how could the same court have arrived at two completely opposite decisions?

The same bench that held on October 15 this year that green firecrackers may be permitted for Diwali and even personal events of celebrations such as weddings in the Delhi-NCR area has been far tougher on farmers when it came to stubble burning.

While stubble burning (which has been banned since 2015) has also been shown to contribute to pollution levels in the region, it revolves around farmers’ livelihoods – and not celebrations – unlike Diwali.

“It is because of them that we get what we eat but that does not mean they should not be brought in to protect the environment of the country. We are not saying you penalise farmers as a routine, do it as a sample to send the message across,” CJI B. R. Gavai had said just four weeks ago.

The bench went on to even ask the Union government why stubble burning could not be criminalised, with erring farmers being given criminal penalties such as jail time.