Key to Beijing’s fight against smog: Accurate forecast a fortnight ahead

In Beijing’s battle against pollution lies lessons for New Delhi, amid the debate in the capital over the effectiveness of the government’s odd-even scheme to curtail deteriorating air quality.

Written by Apurva | Beijing | Updated: November 24, 2017 7:06 am
beijing, air pollution, china smog, delhi pollution, china air pollution State-run media reported that after the orange alert ended November 8, air quality levels were better than expected. (AP File Photo)

On November 2, a text message to all mobile numbers issued in Beijing warned of worsening air quality and that an orange alert — the second highest — had been declared. It meant children and the elderly should stay indoors, certain factories would have to cut production and heavy vehicles would not be allowed to ply Beijing’s roads between November 4 and November 8.

The announcement was made two days in advance to allow the city to cope with an emergency action plan and if possible, hold the smog to lower levels than predicted. State-run media reported that after the orange alert ended November 8, air quality levels were better than expected.

Data from the US Embassy in Beijing, which measures concentrations of PM 2.5 and the corresponding Air Quality Index (AQI), showed pollution levels peaked between November 5 and November 6 (160-210). According to Beijing’s air quality standards, an orange alert means the AQI will remain above 200 for three consecutive days.

Also Read: How Beijing does odd and even, and rations its roads each day

In Beijing’s battle against pollution lies lessons for New Delhi, amid the debate in the capital over the effectiveness of the government’s odd-even scheme to curtail deteriorating air quality. On Wednesday, The Indian Express reported on how Beijing has had its own odd-even policy in place for all weekdays, after the 2008 Olympics, with the scheme kicking in automatically when the highest haze level — red haze alert — is anticipated.

Pan Jiahua, director, Institute for Urban and Environmental Studies, China Academy of Social Sciences, says that while warnings are usually issued 48 hours in advance, China’s climate models can predict air quality up to two weeks in advance. “Technology has come a long way. What used to take two months to calculate and predict some years ago, is now done in days or hours,” he said.

Qiu, a hospitality entrepreneur in Beijing, knows the system well. “A couple of years ago, it was very hard to cope with. But now, announcements are made through multiple systems. On radio, on television, through social media and on social messaging platforms. Anybody living in Beijing will know when an alert is sounded, what to do next and how to plan for the disruption,” he said.

beijing, air pollution, china smog, delhi pollution, china air pollution The construction site of China Zun, planned to be the tallest building in Beijing, is seen amid smog at sunset in Beijing, China. (Reuters File Photo)

According to Pang Jun, associate professor, School of Environment and Natural Resources, Renmin University of China in Beijing, forecasting data is gleaned from environmental prediction and forecasting departments in all regions. “This is based on existing pollution source monitoring, real-time monitoring according to new ambient air quality standards, simulation and analysis of air pollution process, and forecast results of relevant monitoring member units,” he said.

Haze warnings, like the one on November 4, are divided into three levels — yellow, orange and red, respectively, corresponding to moderate, significant and severe haze. AQI is divided into six levels, respectively, with green, yellow, orange, red, purple and maroon, from best air quality to the worst.

Pang says early warning and forecasting was the basis to mount an effective response to air pollution. “Only accurate monitoring, early warning and forecasting of heavy pollution weather like haze, as well as analysis of their sources and causes can help provide the decision-making basis for air quality improvement measures,” he said.

With such advance warning, environment watchdogs have enough time to take emergency control measures, such as reducing production or halting operation of heavy pollution enterprises, to reduce the intensity before pollution is accumulated, he said.

According to Pan, meteorological data and satellite analysis have proved effective. “24 hours a day and 7 days a week, all the time, satellites are recording data from Siberia, the South China Sea everywhere. They record pressure changes, temperature changes and wind direction, how strong the wind is and will be. We know the natural assimilating capacity of a region and this capacity is fixed,” he said.

Since 2014, the Beijing administration has worked with IBM to improve air quality forecasting.

According to IBM’s official website, “The numerous factors that contribute to air-pollution levels (traffic levels, weather, humidity, wind patterns, etc.) are ingested by connected sensors all over China’s capital, and then broken down by artificial intelligence systems. While the data is too complex for human analysts to be able to detect patterns, AI and IoT (Internet of Things) technologies are able to digest big data in order to pinpoint trends.”

This time, well before winter when air quality declines exponentially, three administrations — Beijing, Tianjin and Hebei — announced an action plan to combat air pollution between October 2017 and March 2018. The plan aims to decrease the PM 2.5 concentration in the tri-region by 15 per cent.

“The main tasks include energy structure adjustment, industrial restructuring, mobile pollution source management, non-point source pollution management, heavy pollution weather response, and supervision capabilities improvement. Each city in Beijing-Tianjin-Hebei and surrounding areas has specific measures and deadlines to complete these tasks,” said Pang.

The measures included emergency action during the orange alert. “All regions took some emergency emission reduction measures, successfully controlled the air pollution index which was significantly lower than expected,” he said.

Following the plan, the Beijing municipal government over the course of the four-day orange alert investigated more than 2,000 construction sites, of which 62 were found violating norms. The transport department took action against 3,078 persons for illegally operating trucks ferrying construction material and another 1,500 polluting vehicles were turned away from Beijing.

The contrast with Delhi is stark.

On November 13, in a report submitted to the Supreme Court, the Environment Pollution (Control and Prevention) Authority stressed on the “need for better weather forecasts so that agencies have advance notice of the measures that need to be taken”.

The EPCA report said that “the last information EPCA had on the prevailing weather conditions was on November 6, 2017”. “This did not provide any warning of the kind of anti-cyclonic weather disturbance that was happening in the upper circulatory system and the impending problems it would bring,” it said.

The report pointed out that “across the world, where such smog alert systems are in place, a robust and reliable weather forecasting system is essential for action”.

Speaking to The Indian Express, Anumita Roychowdhury, a member of the Supreme Court-appointed EPCA, said, “Presently, the IMD (India Meteorological Department) provides a forecast, but there is a definite need for better and more accurate forecasting for the city to better prepare for episodes of smog.”

(With Aniruddha Ghosal in New Delhi)

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