• The WHO global air pollution database report that ranked 14 Indian cities among the 15 of the world’s most polluted, in terms of particulate matter (PM) 2.5 concentration, received great attention in India.
• The main sources of air pollution in NCR are more or less of the same nature as in case of Beijing, except that the former has an additional source from stubble burning. 

Measures taken by Delhi to tackle air pollution:-

• Banning the use of private vehicles from November 1 onwards, although drastic, will definitely not be enough to curb pollution.
• Odd-even schemes and, recently, the allowance by the Supreme Court (SC) for only green or zero-emission firecrackers, are the episodic measures that have been used, and still continue to be, to combat this methodical pollution. 
• There have also been instances of ban on construction activities.

Measures taken by Beijing to tackle air pollution :-

• Beijing appears to have turned the tide in its battle against air pollution in five years through an action plan launched in 2013. The air pollution of Beijing of PM2.5 has come down by 54% on average with commensurate improvement in other parameters.
• Research found that emissions from vehicles and dust generated by construction/digging activities and road cleaning etc accounted for most air pollution. Further, 45% of PM2.5 was produced by vehicles only, diesel trucks being the worst offenders. So, Beijing set doable targets and made sure they are achieved.
• The government restricted movement of diesel trucks within the city and major cargo corridors in and out of Beijing, resulting in reduction of PM2.5 pollution by 35%.
• All construction-related activities were banned from November 15, 2017, to March 15, 2018. Carbon emissions reduction was strictly imposed on heavily polluting industries.

Performance of Delhi has been bad due to the following reasons:-

• Transport:- Use of private cars, two- and three-wheelers, and taxis is bound to be much higher in Delhi NCR than in Beijing. Public transport system might not be capable of handling these numbers, especially if the Delhi government continues to overlook the establishment of dedicated bus corridors, despite increased metro coverage.
• SC had ordered building of peripheral expressways so that diesel trucks, not destined for Delhi, do not enter the city. However, these have been completed only now after 13 years.
• Construction:- While Delhi NCR banned all construction activities only for 12-15 days stating November1, Beijing enforced it for four months last year and this year too ensured that measures are taken to suppress dust.
• Upgrading to zig-zag technology of highly-polluting brick-klins industry to be completed before the start of winter has been partially done.
• Also, the ban on use of coal in industries (50,000 still in residential areas) after October 30 is not effectively implemented according to NGT.
• Stubble burning is still the reality because the price of ‘happy seeder’ (`1.25-1.5 lakh) is still prohibitive for small farmers who constitute a majority.
• Odd-even didn’t work because, while vehicles accounted for around 9% of the city’s pollution, just a tenth was due to 4-wheelers that were affected by odd-even.
• Pollution due to the bursting of firecrackers is relatively small, compared to road dust that contributes 56% and 38% of Delhi’s PM10 and PM2.5 pollution, respectively, and crop stubble burning according to a Harvard study, is responsible for 50% of the pollution in October and November in the NCR.

Way forward :-

• Delhi must enforce a long-period ban on construction-related activities in all 15 hotspots right from the time the pollution touches poor category.
• Pollution from other sources has to be controlled by strict enforcement of time-bound ambitious targets and honest monitoring, as Beijing has done.
• Short term measures should be accompanied by measures that increase the forest cover of the land and provide farmers with an alternative to burning the remains of their crops.
• Need to speed up the journey towards LPG and solar-powered stoves.
• Addressing vehicular emissions is within India’s grasp but requires a multi-pronged approach. It needs to combine the already-proposed tighter emission norms (in form of BS VI), with a push for shared mobility and public transport and adoption of alternate mobility technologies. While shared mobility can moderate the demand for individual vehicle ownership and usage, technology solutions today can allow for a sharp reduction in emissions per vehicle. 
• Incentives for adoption of alternate mobility technologies:- India might need to consider pushing for battery localisation. Cell investments would need a long lead-time to materialize.
• Restrictions on elements that contribute negatively to strategic objectives (such as congestion charges on polluting technologies):-
  1. London imposes congestion charges during working hours on weekdays to vehicles entering the city centre.
  2. All these disincentives to traditional cars help in the push for electric vehicles.
• Enabling infrastructure.:- There is an early need to standardise charging infrastructure/equipment to ensure interoperability and make it widespread. 
• Stubble burning issue in North India need to be looked into seriously.
• Attention to non-technological aspects such as urban planning, to reduce driving, and to increase cycling, walking, and use of public transport are needed.
• Tackle road dust:- The Delhi government has talked of mechanised sweeping and water-sprinkling but what would be more beneficial is if the sides of the roads could be paved or covered with grass that holds the soil together and stops the production of the dust in the first place.
• Reducing the vehicle density on Delhi’s streets needs the city to vastly improve its public transport:- More and more people should use bus and metro instead of cars and scooters, as they can carry a lot more people in one journey. Car pool is also a good option.