Delhi has lost the air quality gains of odd and even scheme. Delayed winter will make pollution worse if quicker steps are not taken to sustain the gains, says CSE | Centre for Science and Environment


Delhi has lost the air quality gains of odd and even scheme. Delayed winter will make pollution worse if quicker steps are not taken to sustain the gains, says CSE

Delayed winter will make pollution worse if quicker steps are not taken to sustain the gains, says CSE

Today’s Supreme Court ruling on public transport and all other key pollution sources  can help gather momentum and meet clean air targets  

  • New analysis by CSE shows air pollution is back with a vengeance. The first three working days after the completion of odd and even scheme have seen rapid worsening of air quality – more than 57 per cent jump in PM2.5 levels on the first working day, and have stayed elevated at severe levels

  • Without the moderating influence of emergency action, pollution levels are building up more rapidly. The odd and even scheme has proved that the city needs curbs on high traffic volume to pull down peaking of pollution, reduce congestion that further increase emissions, and cut direct exposure to toxic vehicular fumes. Delhi government should expedite action for more systemic solutions 

  • A series of directives from the Supreme Court today set the terms for pollution control in the entire National Capital Region of Delhi – advancement of Euro VI emissions standards, augmentation of public transport, notice on closure of Badarpur power plant and stronger action on waste burning, construction dust and road dust

New Delhi, January 21, 2016: CSE has analysed air quality data from real-time monitoring of Delhi Pollution Control Board for the entire winter – November 2015 to January 2016 – to assess the benefits of the odd and even scheme and the loss of air quality gains after the completion of the scheme. It has found that the odd and even scheme, although limited in scope and ambit, could still slow down the peaking of pollution even when weather was hostile – no wind, lower temperature and western disturbance in the northern region. Even this benefit was lost immediately after the scheme came to an end as is evident from the air quality trends during the first three working days since the scheme ended.

CSE analysis shows that pollution emergency demands emergency action. But the gains of emergency action will have to be sustained and further enhanced with more immediate systemic changes. Air pollution situation will worsen with the delayed winter. Delhi government should immediately roll out its plan for the remaining part of the winter season and also the action plan to reduce traffic volume on a more sustained basis to allow public transport to perform more efficiently as was possible during the odd and even week. This will also require time-bound implementation of public transport augmentation plan.

Environment Pollution (Prevention and Control) Authority – EPCA – has taken on board the evidences of air quality gains of this scheme for its assessment of the winter pollution and has submitted a report to the Supreme Court. EPCA has also informed the Supreme Court about the status of action on all key sources of pollution.

The Supreme Court today gave a series of directions on augmentation of public transport, advancement of Euro VI emissions standards, notice on closure of Badarpur power plant, stronger enforcement of rulings on trucks and stronger action on waste-burning, construction dust and road dust. All these measures can help speed up action on pollution control to meet the clean air targets and protect public health.

The highlights the CSE analysis of air quality gains and losses

The air quality gains have been lost on the very day after the odd-even scheme came to an end: The gains of odd and even scheme were immediately lost after full traffic was back on the first Monday after the scheme came to a close. This was further aggravated by lower wind speed. On Monday, January 18, the PM2.5 levels shot up by 57 per cent within the day and once again rose to ‘severe’ category. With an average city wide concentration of 277 microgram per cubic metre (cum.), Delhi’s air quality was back in ‘severe’ category. The PM2.5 levels continued to remain in the ‘severe’ category on Tuesday with the levels further increasing to 281 microgram per cum. On Wednesday, there was a reduction to 266 microgram per cum. but not enough even though wind had improved by over 60 per cent since Monday. Without wind, the build-up would have been much higher. On Monday, pollution build up within the 24 hours was massive – by as much as 101microgram per cum. Despite being a windier day this was 35 per cent greater build up on January 18 than the highest observed during odd-even period – a jump of 75 microgram per cum. on January 11.

Similarly, January 1 had lower wind speed than January 18 but the PM2.5 levels rose by just 56 microgramme per cum, which means that the build-up this Monday was 80 per cent higher than on January 1.

Post odd and even scheme days show continuous higher elevated levels throughout the day:  CSE analysis shows that during the fortnight of odd and even scheme, the lowest pollution curve could be seen largely during the afternoon between 2 and 5 pm. But this lowering of curve is getting more flattened in post-scheme days. This means the pollution is building up throughout the day. 

The odd-even scheme has resulted in the lowest pollution peak compared to the previous high smog episodes this winter: This winter out of all the severe smog episodes so far (with several consecutive days in severe category) the peak pollution during odd and even programme has been the lowest. This shows that despite hostile weather conditions - no wind, temperature dip and western disturbance – peak pollution during odd and even scheme was much lower. The earlier smog episodes have seen much higher peaks and much more rapid build up compared to the rise that happened during the first week of odd and even programme. This proves reduced traffic volume has arrested the peaking of pollution. “This validates the importance of emergency action. The fortnight, when the programme was implemented has clearly demonstrated that the peak pollution levels are lower than the normal smog peaks of the season – despite adverse weather conditions, said Anumita Roy Chowdhury, Executive Director, CSE. 

The cleanest day of the season was noted during the odd and even weak when weather was hostile: January 15 – the last day of the odd and even scheme – was the cleanest day of this winter when PM2.5 levels dropped to 155 microgram per cum. The only day when lower levels were recorded was on November 5, 2015 when it had rained in the city. But there was no rain during odd and even fortnight. The benefits continued during the weekend that followed the fortnight with levels further dropping to 130 micrograms per cum. on January 16. But the weekend was also the most windy day of the season. The wind started to slow down on Sunday but due to relatively low traffic, PM2.5 levels rose only marginally to 176 microgrammes per cum.

During odd-even programme day-hours, pollution has shown a faster drop with even lower wind speed: It is clearly evident from the air pollution data that despite the lower wind speed on some days during of the odd-even scheme, pollution fell during those hours. In fact, it is notable that during days before the programme was started, pollution levels had increased when wind speed was low. This brings out the clear impact of the odd and even scheme on pollution levels. Even when there was no wind to blow the pollution away, the scheme succeeded in arresting an upward trend. Both real-time pollution and wind data are from the Delhi Pollution Control monitoring stations.

Satellite imagery shows ‘lightening’ of pollution over Delhi as compared to NCR during odd-even fortnight and studies show that Delhi pollution level was less than neighbouring regions in the odd-even fortnight: Scientists from the Department of Public Health Sciences, University of Miami, US have studied aerosol optical depth or how pollution in the air blocks sunlight by absorbing or by scattering light and prevents direct sunlight from reaching the ground. A value of 0.01 corresponds to an extremely clean atmosphere, and a value of 0.4 would correspond to a very hazy condition. An average aerosol optical depth for the U.S. is 0.1 to 0.15. They have found that this improved in Delhi after the odd-even scheme was implemented. But in areas bordering the capital and the surrounding NCR, there was no effect, and saw 35 per cent worsening. 

Another assessment by a team of researchers from University of Chicago and University of Harvard also finds that the odd-even programme has helped improve air quality in Delhi – by reducing particulate air pollution concentrations by 10-13 per cent in the period. This study found the following: Starting January 1, while absolute pollution levels increased both inside and outside Delhi (for atmospheric reasons, as noted by other commentators), the increase in fine particulates in Delhi was significantly less than in the surrounding region. Overall, it was a 10-13 relative decline in Delhi. During the 8 am to 8 pm period – when the scheme was implemented – the impact is even more visible. Around 8 am, the gap between Delhi’s pollution and its neighbouring regions begins to form and steadily increases until mid-afternoon. Then as temperatures begin to fall and air pollutants are less likely to disperse, this gap starts to close. When focusing on just the hours that the odd-even policy was in effect, the estimate of the authors is that particulate pollution declined by 18 per cent because of the pilot. 

During odd-even fortnight there was increased public transport ridership. With lower traffic volume public transport became more efficient: CSE analysis shows bus speeds increased and this makes them also more reliable modes of transport: road rationing allowed all forms of transport to become more efficient. In this period, buses, autos and taxis could do more kilometres and carry more people. Metro ridership also increased. Bus passengers increased by 8 per cent. In fact, this would have been higher if two-wheelers were also brought within the ambit of the odd and even scheme. This was also possible because of more efficient utilization of the bus fleet. The DTC bus fleet utilization improved from 84 per cent on normal days to 95 per cent during odd-even scheme.

Delhi Metro Rail Corporation (DMRC) has informed EPCA that in any given year January is a lean period for metro ridership due to holidays. While compared to December 2015 there was a drop in absolute metro ridership during odd-even fortnight. But when this ridership is compared to previous January (2015), then during January 1-15 2016, there was an increase of 7 per cent – from 23 lakh per day to 25 lakh per day. DMRC increased the number of coaches from 1,198 as on December 28, 2015 to 1,220 on January 1, 2016. DMRC also increased the number of trips and rescheduled the frequency of trains in peak and off-peak hours. This points towards the need for augmentation of this mode of transport in NCR.

During odd-even fortnight there was a dip in sale of petrol and diesel that which in turn will result in lower pollution: The data obtained by CSE  from Petrol Dealers Association shows that the overall petrol and diesel sales dropped by 4.7 per cent and 7.8 per cent from December 2015 to January 2016.

During odd-even fortnight, studies show dramatic impact in terms of reduced congestion. There is a clear correlation between congestion and pollution: CSE has also reviewed the data generated by other independent studies. The data available from the ‘Traffic Survey and Travel Attributes Study’ conducted by the School of Planning and Architecture’s Department of Transport Planning during odd-even scheme shows substantial reduction in traffic volume and congestion. The survey was carried out in 11 locations along different major arterial roads of Delhi like Gurgaon Expressway, Mathura Road, NH-24, NH-1, Bahadurgarh Road and Ring Road. It found that the average journey speed was as high as 50 kmph during odd and even period as against 20-25 kmph speed on regular days. This was due to reduction in the share of cars on the road. In West and North West Delhi (Punjabi Bagh, Peeragarhi, Rajaouri Garden, Janakpuri, etc), the improvement in speed was not so considerable. The study observed that this was because of already lower share of cars in traffic, construction works along the road, heavy dependence upon two wheelers, roadside encroachments. But the busy Ring-Road experienced about 30 to 50 per cent increase in speeds during the odd-even fortnight. The study also found that the average occupancy in personal cars increased from 1.4 to 2.1 during the odd and even period at major nodes.

CSE compared live traffic updates from Google for January 15, 2016 (during odd-even scheme) and for January 19, 2016 (after the scheme ended). This shows how congestion in most of the roads of Delhi has increased after scheme ended.

Pollution load from cars is lower; per capita emission of car-users is also down during odd and even programme: Both particulate and nitrogen oxide load from cars reduced substantially during odd and even programme – by as much as 40 per cent. A higher share of pollution benefits have come from reduction in diesel cars as is also evident from the sale of diesel in the city. 

Lower congestion and less volume of traffic indicates reduced exposure to toxic pollution from vehicles on roads and close to roadside. It is estimated by the US based Health Effect Institute that the maximum impact of vehicular pollution is upto 500 meters from roadside and 55 per cent of Delhi’s population live within that zone. This has serious public health implications.  Studies by researchers of University of California, Berkeley, have shown that in Delhi the pollution on the road and close to roadside is at least 1.5 times higher and peaks 15 times higher than the ambient concentration. The odd-even programme therefore contributed to the reduction in exposure to toxic fumes. Moreover, higher occupancy of cars due to car-pooling and sharing also reduced per capita toxic emissions of car-users substantially. A shift to other modes can be even more substantial. Vehicles that are second highest emitters in the city are responsible for very high exposure and health impacts. Smog peak reduction will need action on vehicles.

In other countries, duration of the programme is adjusted according to the severity and persistence of severe pollution problem. CSE analysis has found that several countries have implemented odd and even formula as an emergency action to reduce peak pollution levels. Many of those programmes are more stringent in terms of duration, penalty and minimal exemptions. There are evidences of impact on air quality in those global cities. With this programme, several cities have reported a wide range of benefits including reduction in air pollution, reduced congestion, improvement in public transport ridership, etc. Lowering of pollution levels have been reported in different cities. Paris, for instance, that implemented this programme in March 2014 and repeated it in March 2015, saw 18 per cent reduction in traffic volume and 6 per cent drop in pollution levels. But Beijing, that has a longer and a more stringent programme, has shown a 38 per cent reduction in PM10. This indicates that even this reduction is necessary and is possible in the short term to reduce smog peaks.

Delhi must now work to:

CSE analysis recommends further strengthening of emergency action roll-out when pollution levels hit ‘severe’ level. Delhi government should consider more such action sooner keeping in view Delhi is witnessing delayed winter 

Greatly augment public transport, walking and cycling facility so that the city can go car-free more often and as a general practice. The odd and even scheme has shown that congestion and pollution can be reduced if the city has adequate public transport systems.

Use parking restraints, parking charging and taxation measures to reduce traffic volume: The odd and even scheme was a temporary measure to reduce traffic volume to reduce pollution and congestion that had also made public transport more efficient. This means the city needs more systemic solutions to keep overall traffic volume low. Both parking and taxation measures can help to achieve that on a sustained basis. 

Implement Supreme Court directives with urgency to address all key pollution sources: The Supreme Court today directed a slew of orders related to all key pollution sources in the National Capital Region of Delhi. These include quick augmentation of bus and metro; stronger enforcement on diversion of truck traffic; closure notice on coal-based Badarpur Power Station power plant; tighter action on construction dust, road dust and waste-burning. It has also served notice to further advance implementation of Euro VI emissions standards for vehicles. This creates an opportunity for the city speed up time bound action all key pollution sources to meet the clean air target. This should be expedited on an urgent basis, said CSE.

 

For EPCA note submitted to Supreme Court, Click here 
 

For further information, please contact Anupam Srivastava, asrivastava@cseindia.org, 99100 93893

 

 

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