"See this street! Look!" says Bai Xiao Cheng as gestures toward his village's main concrete road.
It's barely half a mile long, and apart from one small grocery store, a few home entrances and a handful of parked cars, it has no notable features. That for Bai, is precisely the point. "It's very clean, very good!" he smiles.
This time last year the streets of Tangzitou village were strewn with coal. Black dust covered the ground and coal was piled high by doorways and courtyard entrances. It had been the village's main source of energy for cooking and heating in the village, an hour north of downtown Beijing. Winter temperatures plunge as low as one degree Fahrenheit.
"You had to refill the coal several times a day and it was extremely dirty and very tiring. We stored it in our homes and each winter we needed tons of it," says the 61-year-old.
That changed in September of this year, when a Communist Party secretary informed the village's 300 residents they would be converting to natural gas. "They confiscated our coal ovens and installed gas systems instead. Coal was forbidden, and that was that!" says Bai.
The optimism expressed by Bai is felt across many parts of China. In rural villages, there's a sense that the air is improving because of government drives to replace coal as a household energy source.
But for urban residents, a more pressing issue is pollution from power plants and factories. The government has made attempts to regulate heavy industry. But in the winter of 2018, there are concerns about backsliding.
Since 2017 the Chinese government says around 4 million homes in the country's north have been converted to natural gas. Forcing households to make the switch from dirty-burning fuel sources such as coal, wood or corn stalks, to cleaner energy sources such as gas and electricity, is just one of the Communist Party's strategies in its long-running war against air pollution.
According to research published this month in the journal PNAS, it works. The study, conducted primarily by Beijing's Tsinghua University and the University of California (UC) Berkeley, found that transitioning to cleaner fuels cut the average person in China's exposure to PM2.5 — the most dangerous particles contained in air pollution — by 47 percent. Using World Health Organization data relating to major diseases associated with air pollution, such as chronic obstructive lung disease and lung cancer, the researchers also calculated that China's energy conversion has helped prevent 400,000 premature deaths annually.
"Household air pollution has a bigger effect on health, because emissions from households are right next to the people and the impact in terms of exposure is higher," says UC Berkeley professor Kirk Smith, a co-author of the report.
Reducing household emissions, he says, also improves general air quality. "The pollution starts in the kitchen, but it soon goes outdoors. So when you improve the household fuel situation by swapping to cleaner fuels you help villagers directly, but you also progress in reducing outdoor air pollution."
Lead analyst of Greenpeace's Global Air Pollution Unit Lauri Myllyvirta agrees, saying the approach was a major contributor to the reduction in air pollution around Beijing last winter. "Last winter was enormously good, they exceeded targets," says Myllyvirta.
But on a national level, he says that stricter emissions standards for factories and power plants played an even more important role in improving air quality. According to hourly data collected by China's Ministry of Environmental Protection and compiled by Greenpeace, "levels of PM2.5 have decreased by around 30 percent over a period of five years which is a huge accomplishment," he told NPR.
It was on March 4, 2014 that Chinese Premier Li Keqiang first announced to China and the world that the country was waging war against smog. The declaration went against a long-standing policy of sacrificing the environment for the sake of economic growth.
Liam Bates is the CEO and founder of Kaiterra, a Beijing-based company which makes portable indoor air quality monitors and also independently collects data on Beijing's air pollution. He says the moment marked a turning point in China's air pollution awareness.
"Before then people thought the smog was [a] cloud," he says. Previously the topic was considered taboo and often censored on social media. Li's speech, Bates says, was an "admission that this thing exists and we're fighting it — and it's fine to talk about your enemy right?"
The following year posts about "smog refugees" leaving Beijing began to go viral on China's internet. "It sounds like an exaggerated term," says Bates. "But it's accurate. All these smart and capable people were reportedly leaving the capital" because they feared for their health.
"The government took notice," he says.
A few years earlier in 2013, China's Academy for Environmental Planning pledged $277 billion to combat urban air pollution. The "Airbourne Prevention and Control Action Plan (2013–17)" focused on the country's worst-affected regions — Beijing, Tianjin and Hebei — its industrial heartland. Funds were used to implement strict emissions policies.
Today Bates says Beijing residents are highly-educated when it comes to air-pollution. "You can find anyone on the street and ask, "what's PM2.5?" and they'll know what it is. In very few places in the world does that happen."
But knowledge doesn't always mean power. At 8 a.m. on a Monday morning in November, researcher Zou Yi is standing on a footbridge above a congested Beijing Central Business District highway. The founder of the nonprofit group Beijing Air Now is snapping pictures of surrounding buildings on his phone, something he's done every day for the past five years. Today Beijing's Air Quality Index has exceeded 300 µg/m3 (the microgram concentration of air pollutants per cubic meter of air) — a level described as "hazardous" by the World Health Organization. Heavy grey smog obscures much of the city skyline.
"I share daily pictures of Beijing's sky to my organization's social media followers so they can compare and contrast conditions. It's also a record for my own research," says Zou Yi, who posts pictures alongside daily air quality readings provided by the government.
Zou Yi has described annual improvements in China's air quality as "remarkable" but says the work is far from over. "We still have days where the air is really horrible. A lot of the time it's because of weather conditions that we can't control," says Zou.
Liam Bates says a region's geography can exacerbate bad air quality, and cities like Beijing are often at the mercy of the wind. "It's basically a bowl. [Pollution] stops here and doesn't go away until the wind blows from the northwest."
China's national observatory has this year warned that "unfavorable weather conditions" such as weak wind and high humidity would give way to worsening air pollution levels this winter. With the return of cold temperatures and the beginning of the country's heating period in November that's already proving to be true.
Referencing government air quality data, Zou Yi says Beijing's air quality last month bore a stark contrast to levels in November 2017. "November shows a poor performance with a 41 percent sharp rise in levels of PM2.5 compared with the same period last year," he said in a text message to NPR.
Though Lauri Myllyvirta of Greenpeace says weather does play a role, he says it's not the main reason intense air pollution has returned to the country's north. "This winter restrictions on industrial output are much weaker," he says.
Facing a slowing economy and increasing pressure from its trade war with the United States, China has relaxed many of last year's strict measures. In September the Ministry of Ecology and Environment removed blanket bans on heavy industry production. Monitoring was decentralized, with local governments now allowed to set their own targets.
Myllyvirta says the government appears to be shifting its priorities. "There was a pushback against measures taken last winter, which were criticized for being "one-size fits all," he says.
"The problem is that economic and policy and environmental policy are pushing in different directions. We have an economic policy which is very supportive of heavy industry and construction."
Rather than relying on strict emissions curbs which force factories to halt or drastically reduce production, Myllyvirta says China's economy needs to speed up its pivot away from manufacturing toward higher quality industries and services.
"The worst-case scenario would be starting another massive stimulus package like there was in 2008 and 2015, which would see a boom in construction and heavy industry — that's the scenario where we could see things going backwards," he says.
Kirk Smith isn't surprised the Chinese government is this year giving in to business demands. "They've achieved an extraordinary transition in a short period of time. It's expected that there would be two steps forward, one step back as special interests or industries complain."
Hazy But Hopeful Forecast
But in Tangzitou village, Bai Shao is not discouraged. He shows off his new home gas system with pride. Despite paying three times more for heating than he did with coal — the equivalent of about $500 per winter — he says he's pleased the village made the switch. "Nobody says coal is better, we love using gas. It's freed up our time because we don't need to go refill the coal, and the temperature is constant and warmer."
The higher cost, even with government subsidies, means continual enforcement of the switch is crucial. But that's not the only issue. Uneven distribution of gas resources to poorer or more rural areas versus urban centers — and the state's ability to secure adequate supplies in the long-term — are also concerns. According to national customs statistics, China currently imports as much as 39 percent of its natural gas supply, and in recent years, demand for gas has outstripped supply increases.
Bai, however, says there's no point worrying about tomorrow. From where he stands today the indoors are warmer and the skies above are bluer.
"All these government departments and districts have made a lot of effort to improve the air quality. The smog days are fewer than before and now we see blue sky, the long-missed sun," he says.
Katrina Yu is an Australian journalist, video producer and writer who has been based in China for five years. Her reports have appeared on the PBS Newshour, France24, Al Jazeera Online and SBS Australia.