China is claiming significant progress in its battle against smog despite an increase in coal consumption for the first time in four years.
In an upbeat assessment on March 17, the official Xinhua news agency reported a sharp drop in sales of the ubiquitous face masks that city dwellers have worn to keep deadly small particles known as PM2.5 out of their lungs.
According to the report, the bad news for mask makers is due to good news for air quality, "as some Chinese cities enjoyed the clearest winter sky in five years thanks to sustained pollution control efforts."
In its broad survey of 338 cities, the Ministry of Environmental Protection (MEP) found that average PM2.5 density in 2017 fell 6.5 percent from a year earlier to 43 micrograms per cubic meter.
The decline exceeded the six-percent decrease in PM2.5 concentrations that the MEP reported for 2016.
Li Ganjie, now minister of ecological environment in the reorganized government, noted even lower readings in January of 34 micrograms per cubic meter in Beijing, the best since 2013.
Xinhua also cited positive findings by the Energy Policy Institute at the University of Chicago, highlighted by The New York Times. In a recent opinion piece, institute director Michael Greenstone concluded that "China is winning" its war on pollution "at (a) record pace."
The reports of progress in the past year may be all the more remarkable in light of government economic and energy indicators associated with smog, nearly all of which rose at faster rates in 2017.
According to the National Bureau of Statistics (NBS), China's gross domestic product climbed 6.9 percent, overshooting the government's 6.5-percent target and accelerating from a year earlier for the first time since 2010.
Total energy consumption rose 2.9 percent, more than double the 1.4-percent increase reported for 2016.
Coal consumption edged up 0.4 percent in 2017, compared with a year-earlier drop of 4.7 percent.
Consumption of crude oil jumped 5.2 percent, compared with a 1.3-percent increase in 2016, as estimated by S&P Global Platts energy news.
Meanwhile, use of natural gas soared 15 percent, slightly less than the 17.4-percent gain in 2016 due to shortages of the cleaner-burning fuel. The increase in gas had been expected to reduce coal burning, but consumption of both fuels rose last year.
If the official figures are correct, China may have pulled off an unlikely feat last year by cutting smog while expanding the economy and energy consumption at a faster rate at the same time.
A different view
But a Greenpeace East Asia report in January offered a different view of last year's events.
The environmental watchdog found vastly uneven results among cities and provinces that reported data at the time of the study.
Beijing, Tianjin and 26 nearby cities made an impressive 33.1-percent improvement in PM2.5 levels late last year as a result of a winter "action plan."
But the more distant provinces of Heilongjiang, Anhui, Jiangxi and Guangdong suffered PM2.5 increases ranging from 4 percent to 10.4 percent in 2017, Greenpeace said.
In the fourth quarter, PM2.5 readings plunged by a dramatic 53.8 percent in Beijing alone.
But during the first three quarters of last year, average PM2.5 rose 6 percent from a year earlier in Beijing and selected cities, while in industrialized Hebei and Shanxi provinces, concentrations climbed 13 percent and 23 percent respectively, the study said.
The numbers suggest that the government pushed stimulus policies to boost the economy before this year's key political meetings.
At the same time, it ordered steel production cutbacks and winter coal bans for heating in 28 northern cities as part of an all-out effort to clear the skies in Beijing.
The campaign appears to have shifted coal-burning and smog-causing production to parts of the country where air quality was a lower political priority.
Despite the winter restrictions on production in the northern region, China's overall output of crude steel jumped 5.7 percent last year after slow growth of 1.2 percent in 2016.
Even in the 28 northern cities, the anti-smog push was only partially successful as gas shortages and unfinished distribution projects forced the National Development and Reform Commission (NDRC) to allow coal-fired heating to resume in December after widespread complaints.
Last year, China's coal production rose 3.2 percent, reversing a 9.4-percent decline in 2016.
Although the 338-city survey shows progress in lowering PM2.5 concentrations, the average levels remain 72 percent higher than guidelines set by the World Health Organization.
Still, the survey suggests that China's smog-control efforts have been working. The government credits tougher inspections and environmental enforcement.
At a press conference during China's recent legislative sessions, Minister Li said that more than 20,000 individuals had been "held accountable" for environmental infractions in the past two years.
Full of tricks
Among the most serious violations, inspectors in January found that officials in Jiangxi and Henan provinces and the Ningxia Hui autonomous region had used mist cannons to spray air pollution monitoring sensors and report lower readings.
The falsification may shake confidence in some provincial air quality data, although the full extent of the fraud is unclear.
On March 30, Ministry of Ecology and Environment spokesman Liu Youbin said inspectors found the water spray trick was used on nine monitoring stations in seven cities located in six provincial-level regions.
An undisclosed number of officials were dismissed or demoted for the falsification while others received warnings, the official English-language China Daily said.
But stricter enforcement of pollution controls at coal- fired power plants could help to explain how China reduced smog despite higher coal consumption.
"Technical measures taken on the stacks of thermal power plants and other industrial plants can significantly reduce pollutant emissions, and this pollution can decline as coal use rises," said Philip Andrews-Speed, a China energy expert at National University of Singapore.
Another explanation is more favorable weather conditions, which are beyond the government's ability to control.
"Weather in the form of strong northerly winds can make a great difference by dispersing the pollution rapidly," said Andrews-Speed by email.
In its study, Greenpeace said the fourth-quarter decline in PM2.5 among the 28 northern cities was due to favorable weather and the anti-pollution action plan "in roughly equal parts."
A heavy smog attack late last month served as a reminder that the wind can also cause severe problems.
On March 28, Beijing monitors reported PM2.5 levels up to 193 micrograms per cubic meter, prompting an orange alert, the second-highest level of warning.
Officials blamed wind-blown dust from Mongolia for spreading smog over a wide area.
Although sandstorms were cited, environmental officials said that heavy industry also played a part as the winter cutbacks on production ended.
The National Joint Research Center on Air Pollution Causes and Control said that "many of the companies whose production was restricted have resumed normal operations, resulting in an obvious increase in air pollutants from industrial sources," China Daily reported.
Andrews-Speed said that the differing viewpoints of Greenpeace and the government on the PM2.5 data may both be valid.
"Xinhua takes a national average, which has declined," he said. "Greenpeace identifies a few regions where it has gotten worse."
But the unpredictable contribution of weather conditions to last year's positive results may raise concerns that the improvement will not be repeatable if China continues to increase coal consumption in 2018.
In the first two months of this year, coal production rose 5.7 percent, according to NBS data, outpacing the 2017 growth rate and suggesting continued robust demand.
Thermal power production through February was also up 9.8 percent, more than double the growth rate of 2017.
The rising rates may be a sign that the government believes that China can "have it all" — high economic growth and production with blue skies and pollution control.