Beijing’s air quality meets national standards: a major milestone in China’s war on smog

Beijing’s air quality met China’s national standards in 2021, for the first time since monitoring started, and the first time this century. The average concentration of PM2.5, the most dangerous pollutant, and the number one focus of China’s efforts, fell 13% on year, to 33 µg/m3, against a national standard of 35.

The concentrations of PM2.5 have come down two thirds from close to 100 µg/m3 a decade ago, an enormous achievement. Even so, particulate pollution levels in Beijing remain far above WHO guidelines — almost seven times as high to be precise — and constitute an ongoing health risk for residents. The city continues to experience serious smog episodes, even if not as severe as during last decade.

PM2.5 pollution levels have fallen across China since the issuance of the National Air Quality Action Plan in 2013. The improvements have been the fastest in Beijing and the old industrial belts around Beijing, Shanghai and the Northeast. The provinces where the central government has encouraged coal-based industrial expansion, such as Xinjiang, Sha’anxi, Shanxi and Inner Mongolia, have improved as well but more slowly.

Can we trust the data?

The improvements are real — the government’s air quality reporting is in line with satellite observations and, for Beijing, with readings reported by the U.S. embassy. It’s also notable that the improvements are broad-based, happening across the industrial belt surrounding Beijing, as well as in much of the rest of the country.

The government’s old, pre-2012, air quality monitoring system was notoriously unreliable and prone to manipulation. The situation in Beijing where people would trust the U.S. embassy more than the government was untenable for the government, and a new nationwide system was created that reports measurements in real time and makes manipulation by local officials almost impossible.

It’s not for lack of trying, with famous cases of stuffing cotton balls in the monitor inlet or setting up mist cannons outside government buildings housing the monitoring equipment. But such desperate gimmicks just show that once a monitoring station reports a measurement into the digital system, there is no way for local officials to manipulate it.

In my experience, people in Beijing and other cities were initially skeptical, but by 2017 at the latest, the reductions in pollution levels were easy to see with your own eyes and feel in your throat. For example, Beijing’s western mountains can often be seen from the city now, an extremely rare sight ten years ago. Of course, the air is still not clean and many people’s health is still affected, but people have come to expect ongoing improvements.

What drove the improvements?

Most of the pollution in Beijing, like in most cities, originates outside of the city. Beijing is surrounded by the largest concentration of coal-burning industries, especially steel, in the world, and one of the largest concentrations of coal-fired power plants. More coal is burned within a few hundred kilometers of Beijing than in the entire United States.

Controlling the emissions from these coal-burning industries has been the key to improving Beijing’s air quality. The importance of tackling emissions from surrounding provinces is also one reason why the improvements have been so broad-based.

The most important drivers are:

  1. strong emissions standards and control technologies, first applied to power plants and now also to steel and other high-emissions industries
  2. elimination of coal-based heating and cooking in individual houses, and replacement with district heating, gas and electricity
  3. slowdown in coal consumption growth since 2013 — before that, improvements in emissions controls were overwhelmed by the increase in the amount of coal-burning.

While these are the most significant individual measures, the government has very comprehensive action plans in place on all levels from national to city and district level, addressing all emitting sectors.

Beyond specific measures and sectors, the continued improvement in air quality should be attributed to vastly improved environmental governance and enforcement. Circumvention and violation of standards and policies used to be rampant but is now caught quickly. Government officials at all levels have a strong incentive to ensure progress and compliance.

Average satellite-based measurements of sulfur dioxide, a key pollutant from coal burning and a key contributor to PM2.5 formation. Levels fell precipitously due to the installation of scrubbers in power plants and industrial plants, and the elimination of uncontrolled, small-scale coal-burning in households. Dobson units.

What motivated the government to act?

The public concern and outrage over air pollution reached a boiling point in the winter 2012–13. Air quality had improved due to measures implemented before the Beijing Olympics in 2008, and the industrial slowdown caused by the global financial crisis. The slowdown was followed by an unprecedented construction stimulus that pushed air pollution levels back up, culminating in horrendous smog episodes in late 2012.

It was the experience of relatively clean air in late 2000s and then the return of the smog that caused the patience of many citizens to grow thin. Parents were sharing heartwrenching stories about listening to their children cough at night, and PM2.5 became a household word.

Air quality monitoring by the U.S. Embassy, and the use of the U.S. air quality index to report the measurements, played an important role. Pollution levels that the Chinese government scale would label “lightly polluted” were “very unhealthy” or “hazardous” on the U.S. scale.

At this point, the government decided it had to tackle air pollution effectively and on the regional level. The national air pollution action plan issued in 2013 required the key regions to cut coal consumption in absolute terms, an unprecedented step after decades of breakneck growth, and achieve significant improvements in air quality by 2017.

A quirky but significant side story to the public debate about air pollution in China is how the U.S. Air Quality Index ending at a reading of 500, a level commonly breached around Beijing in the winters of early 2010s, gave rise to an “emergency threshold” in how air pollution levels are perceived.

Ongoing health risk

Even if Beijing now complies with the national air quality standard for PM2.5 level of 35 µg/m3, this level still implies an approximately 45% increase in the risk of lung cancer, 40% increase in the risk of stroke&adult diabetes, 70% increase in ischaemic heart disease and doubling the risk of acute lower respiratory infections, based on latest risk models.

Obviously that’s much better than things were in Beijing at their worst, at around 100 µg/m3. That level means an about 70% increase in the risk of deaths from chronic diseases, compared with 30% at current levels. 100 µg/m3 is where many South Asian cities are still at.

Will the improvements continue?

Looking forward, there are strong incentives for local governments to post annual improvements in air quality, and citizens have come to expect continued improvement, so the impetus is there.

Air quality improvements to date have relied on improved filters and scrubbers, while coal and other fossil fuel consumption has continued to grow. It will become harder and harder to improve air quality through this route, given that the low-hanging fruit has been picked a long time ago. Further improvement will require a shift from coal and oil to clean energy. China’s environmental ministry (MEE) is quite clear about this and is referring to it as improving the energy structure and economic structure. The joint control of air pollutants and CO2 is an important area where the MEE could use some of the formidable monitoring and enforcement capacity created for the air pollution fight to drive further progress on both climate and air quality.

Are there lessons for other cities and countries?

While every city and country will need to find implementation strategies that match their specific political and economic systems, and mix of emissions sources, there are a few universal lessons from China’s experience — and that of other regions that have succeeded. Those include:

  • Creating a comprehensive and reliable air pollution monitoring and emissions reporting system, with both real-time and time-averaged data easily accessible to the public and to researchers
  • Setting targets & timelines for air quality improvement with clear accountability. It’s not enough to have an air quality standard, unless there are interim targets and timelines to meet it. China has been setting annual targets for all key regions and tracking progress towards them on monthly and yearly basis.
  • National&regional air pollution action plans targeting all key sectors and pollutants. Cities can’t do this alone, because so much of the pollution comes from outside the city, so creating regional action plans is crucial. Action plans need to be based on a scientific assessment of the sources of air pollution and address all significant source sectors. It’s far too common for cities to fixate on one or two sources while emissions from others increase.
  • Strong emission standards and enforcement: power plants, industry and transport. One of the key breakthroughs in China was creating a continuous emission monitoring system for major industrial emissions sources and automatically fining emitters every time they violated emissions limits.
  • Moving beyond end-of-pipe measures: clean energy, sustainable transport, energy efficiency and other ways to eliminate dirty fuels, rather than filter out some of their pollution. China is still working on this, but eventually it becomes a necessity — filters and scrubbers only go so far.