Delhi's Graded Action Plan (GRAP) on air pollution, including the odd-even vehicle scheme, is set to make a comeback this winter | Photo: Twitter

Odd-even scheme returns to Delhi, but how effective is it?

Ahead of Delhi’s dreaded winter smog, chief minister Arvind Kejriwal plans to bring back the odd-even scheme for private vehicles on roads from November 1 to November 14. For two weeks, private vehicles will only be allowed on alternate days, depending on whether their registration plate ends in an odd or even number. Delhi will also introduce 1,000 electric buses to fight pollution, the CM said.

The Delhi government claimed that “emergency” anti-air pollution measures such as the Graded Response Action Plan (GRAP) and the odd-even traffic scheme had brought pollution levels down by 25% compared to levels before 2016. But experts say it is wrong to compare levels before and after 2016. Until 2015, air pollution monitoring was weak and data was not available for most stations. The CSE report, which the Delhi government cited, says, “There are data gaps for the older stations operating during 2010-2014 and major gaps in data for the year 2014-2015.”  

United Residents Joint Action (URJA), an apex body of around 2,500 resident welfare associations (RWAs) in the Capital, filed an RTI in 2018 with multiple departments accountable for GRAP after it found the plan non-effective in reducing extreme winter pollution. The analysis found serious gaps in enforcement and understanding of GRAP amongst officials. URJA pointed out that in 2018, Delhi had five good air quality days, 66 moderately polluted, 145 poor quality, 57 very poor quality and 92 severely polluted days, according to the Central Pollution Control Board (CPCB). URJA report says since exposure to pollution for just an hour is sufficient to trigger diseases and respiratory issues, aggregated average numbers over three years hide the hassle and gravity of impact from sudden spikes and sustained exposure

 According to CSE analysis, winters of 2016-17 and 2017-18 (October to February) recorded 94.6% and 92.6% ‘severe to poor (less polluted)’ air quality days, respectively. CSE analysis of CPCB data indicates 94.6% and 92.6% (140 and 137 out of 148 days) ‘severe to poor (less polluted)’ air quality days during winter months of 2016-17 and 2017-18, respectively.

The CPCB had found that while Delhi had only three out of 17 industries complying with its pollution norms, there are over a 1,000 industries in the National Capital Region (NCR) that were not compliant. In fact, the National Green Tribunal (NGT) had fined the Delhi government for Rs25 crore for not taking adequate action for four-and-a-half years.

Emergency (GRAP) or medium-term (CAP) measures have resulted in zero good quality days during winter months.

How has the odd-even scheme fared in Delhi so far?

According to CSE data in 2016, Delhi implemented the odd-even scheme twice in 2016. The first time it was successful, but in the second leg from April 15-30, air pollution levels tanked during the first nine days, but then saw an unprecedented rise from April 22. The Supreme Court has ordered Delhi to get at least 11,000 buses and it has around 5,500.

Several studies, including by the World Health Organisation (WHO) have shown Delhi to be the world’s most polluted capital city, which has been battling vehicle and industrial emissions, dust from building sites, and smoke from the burning of rubbish and crop residue in nearby fields. According to the WHO air-pollution ranking of more than 2,600 polluted cities world wide, 14 of the 18 most polluted cities on the planet are in northern India.