How Does China’s Air Pollution Compare with Air Pollution Elsewhere?

It depends on who is doing the surveying (e.g., the WHO or World Bank), the metric used (e.g., PM10, PM2.5, or percentage of the country’s population exposed to unhealthy air), and the period covered (one year or multiple years, and which particular year or years). By virtually any account, however, China is near or at the top of the list of the world’s most polluted countries.

India, Pakistan, Afghanistan, Qatar, Iran, and Bangladesh, in terms of their particulate matter levels, tend to cluster with China at the top of these lists. In fact, Delhi, according to the WHO’s 2016 report, is the most polluted city in the world, with an average annual PM2.5 reading of 153 (compared to Beijing’s 56). Twelve other Indian cities appear on the WHO’s list of the world’s 20 most polluted cities. No Chinese city even makes the list.

But while India’s cities may be smoggier than China’s, the urbanized population of India represents a relatively small 33% of the country’s people. In China, a full 56% of the population is now urbanized, so exposure to polluted air is considerably more widespread. And although Qatar and Iran are, to be sure, highly urbanized, the total number of affected people p. 60↵in these countries is quite small by comparison with China. We can perhaps best characterize the pollution contest this way: cities in India have some of the most polluted air in the world, but air pollution in China is more extensive and poses a health threat to more people.¹

But India, a country that lags far behind China by all economic indices, is now—as China was for the past three decades—bent on revving up its economy and reducing the poverty that is rampant among its people. Looking to follow in China’s economic footsteps, the government in New Delhi has exhibited restrained enthusiasm for taking environmental measures that might hinder the country’s economic growth. India would do well to learn from the Chinese experience and give thorough consideration to the environmental consequences, long-term ones as well as short-term ones, as it looks to accelerate its economic development.²

What Are the Major Pollutants in the Air?

Carbon dioxide (CO₂), particulate matter (both PM10 and PM2.5 [see below]), carbon monoxide, sulfur dioxide, nitrogen dioxide, mercury, and ozone are the major pollutants in China’s air. They come from a variety of sources, but most especially from coal combustion, vehicle emissions, and construction work. Coal combustion—in power and industrial plants and for home heating and cooking—produces significant amounts of CO₂, sulfur dioxides, nitrogen oxides, and particulate matter. Vehicles—cars and trucks, especially those that run on low-grade diesel fuel—are responsible for emissions of carbon monoxide, hydrocarbons, nitrogen oxides, and particulate matter. Construction, particularly on the massive scale taking place in China, kicks up a tremendous amount of debris and dust, which adds to the particulate matter suspended in the air.

The government periodically targets what it claims, perhaps in earnest, to be other sources of significant pollution as p. 61↵well. Since 2013 it has cracked down on open-air barbecuing, confiscating grills from street vendors and destroying them, and since 2015 it has requested that the people refrain from setting off fireworks, especially during the Lunar New Year. “Anti-pollution” campaigns like these inevitably invite ridicule by much of the public, which sees them as distractions by a government wishing to avoid addressing the real problem: industrial pollution. In January 2015, one official in the city of Dazhou even blamed the city’s air pollution problem on the local practice of smoking bacon. (Respondents on the social media site Weibo were quick to point out that locals had been smoking bacon for centuries, long before the city’s air turned to smog. One quipped, “Only a pig-headed person would think that air pollution was caused by smoking bacon.”)

The pollutants from these three major sources—coal combustion, vehicles, and construction—largely make for the grimy air seen in images of cities like Beijing, Shanghai, Hangzhou, Lanzhou, Xi’an, Tianjin, Chongqing, Shijiazhuang, and Linfen that are broadcast around the world. These pollutants do not simply dirty the air, turning daytime into nighttime in these places; they also wreak havoc on public health (see Chapter 8). A 2015 Greenpeace study based on data from 2013 found that in the 31 provincial capitals, 1 out of every 7 deaths could be attributed to air pollution. This means that simply breathing the air in China poses the same risk of premature death as smoking cigarettes.³

What Exactly Is PM2.5?

PM2.5 refers to particulate solids or droplets—dust, dirt, smoke, organic chemicals, metals, and so on—that are less than 2.5 micrometers in diameter and are suspended in the air. PM2.5 has multiple pollution sources: manufacturing, coal burning, vehicle exhaust, waste incineration, biomass burning, sandstorms, construction dust, fertilizer application, chemical processes that occur in the atmosphere (e.g., sulfur dioxides, p. 62↵nitrous oxides, and ammonia can be transformed into the particulates sulfate, nitrates, and ammonium when exposed to light), and even barbecue grilling. Of these, coal combustion, vehicle exhaust, construction, and sandstorms are the biggest perpetrators.

PM2.5 is not, then, a single pollutant but a mixture of pollutants that come together in particle or droplet form. Most particulate matter results from chemical reactions between pollutants in the air (called secondary particulate matters). As a consequence, the precise composition of particulate matter varies from place to place and day to day. Scientists at the Research Center for Eco-environmental Sciences of the Chinese Academy of Science are now engaged in a long-term research study of PM2.5 “to investigate how it emerges, evolves, and can be reduced . . . Scientists will identify the types and sources of key pollutants, unravel the different formation mechanism of haze in different parts of China, and develop a suite of source-controlled based technologies for the monitoring, forecasting, and management of haze.”⁴

PM2.5 poses the most serious and immediate health threat of all the pollutants in China’s air today. When people breathe, these particles enter their respiratory system and can travel into their lungs and even their bloodstream. At a miniscule 2.5 micrometers in diameter—1/30 the width of a human hair—these tiny particles can make their way deep in people’s lungs and lodge there. As we will see in Chapter 8, scientific studies in the past 20 years or so have shown that PM2.5 is closely linked to a range of health issues, including shortness of breath, asthma attacks, acute bronchitis, neurological disorders, decreased lung function, lung cancer, heart attacks, and premature death.

Particulate matter comes in a larger size as well, PM10. At 10 micrometers or less, these particles are coarser than PM2.5. They too can harm human health, but because of their larger size they are more easily combatted by the human body and cannot penetrate so readily into the lungs or bloodstream.

p. 63↵On account of the threat it poses to public health, PM2.5 has become the main measure of China’s air quality. The scale measures from 0 to 500, which represents the micrograms of PM2.5 per cubic meter. Zero is the best, 500 the worst. Beijing has set what it calls “interim targets,” temporary national standards, for PM2.5 levels: 70 μg/m³ for a 24-hour period and 35 μg/m³ for the year. These are considerably higher than what the WHO recommends: 25 μg/m³ for a daily reading and 10 μg/m³ for an annual reading. The “interim targets” are an acknowledgment that China has a way to go to meet the current WHO standards and would benefit from intermediate targets (as I write this, Beijing’s reading is 406). By comparison, the US guidelines are 35 μg/m³ for a 24-hour period and 12 μg/m³, higher as well, though only slightly, than the WHO recommendations.

In January 2015 Greenpeace China released a study of air pollution in 190 cities. Every single one exceeded the WHO standard of 10 μg/m³, and 179 exceeded China’s own national standard of 35 μg/m³.⁵

How Did PM2.5 Become a Household Term in China?

Mention PM2.5 to most Americans and they stare blankly, wondering whether it is the name of a rock band or perhaps a classified missile system. The Chinese people, on the other hand, are all familiar with the term: by the end of 2013 it was the third most popular meme on social media sites.

Here is the backstory. In 2008 the US Embassy in Beijing installed an air-monitoring device on its roof, tweeting out PM2.5 levels (@beijingair), with brief commentary, on the hour to inform its employees and US citizens of the severity of the pollution in the vicinity so they could plan their day’s activities—and their children’s activities—accordingly. Chinese authorities had yet to recognize PM2.5 as the standard measure for air quality; the less hazardous PM10 was the common measure, the one reported to the public. In 2009 the p. 64↵Beijing Ministry of Foreign Affairs filed complaints with the embassy saying that tweeting information about China’s air quality was a violation of Chinese law and demanding that the embassy stop the practice. The embassy persisted. The tweets were picked up by Chinese internet users (“netizens”), who retweeted the information much more widely on China’s social media sites. Because these tweets focused on PM2.5 as well as PM10, they revealed the air in Beijing to be significantly more polluted and dangerous than what was reported by the Chinese government. People demanded that the government provide the same information as the US embassy. And in December 2011, influential real estate mogul and social media commentator Pan Shiyi carried out an informal poll among his millions of followers on Sina Weibo, asking whether they agreed that “the authorities should adopt the PM2.5 standard this year.” Tens of thousands of people responded, with 95% of them expressing agreement. One month later, in January 2012, Beijing’s own Environmental Protection Bureau began publishing air quality data that included PM2.5 levels.⁶ Whether—and how much—Pan Shiyi and public opinion might have played a role in Beijing’s decision to publish PM2.5 information, we cannot know.

The story continues: one year later, in January 2013, the now-notorious “airpocalypse” rocked China, hitting the capital especially hard. The smog was horrific; before deciding whether to go outdoors, send a child off to school, take a jog, or even open windows, people would consult the air quality index, especially PM2.5 levels. They actively turned to social media to share information—and vent—about the pollution and, especially, the stratospheric PM2.5 levels. Private citizens began developing air-quality apps, some showing both the levels recorded by their city governments and the levels recorded by the US Embassy and consulates. These days, almost every smartphone user in China has an air-quality app at the ready, and there are now air monitors recording PM2.5 levels in more than 360 Chinese cities.

p. 65What Was the Airpocalypse?

As we noted above, China measures its PM2.5 levels on a scale of 0 to 500 micrograms per cubic meter. You will remember, too, that 500 μg/m³ is 20 times higher than the level considered safe to breathe by the WHO. During January 2013 in northern China, especially the area around Beijing, PM2.5 readings were regularly “off the charts” or “beyond index,” meaning they exceeded the air-quality index limit of 500. There were many days when readings were in the 700 to 900 range. (One day it hit 993; by comparison, on the same day in New York City the reading was 19.) Over the course of the month, hundreds of flights in and out of Beijing were cancelled, industrial plants were shuttered, roads were closed, schools were shut down, cars were ordered off the road, and hospitals were overflowing with children suffering from respiratory problems.

To say that this smog caught China’s attention, and indeed global attention, is an understatement. Every day, media in China and across the globe broadcast pictures of Beijing’s soupy, sooty air, which darkened daytime skies and cloaked even the most massive skyscrapers in impenetrable haze. A report by Bloomberg that received widespread attention at the time showed that the daily average PM2.5 reading of the air over Beijing in January 2013 was 30 μg/m³ higher than the average daily reading of the air in a typical smoking lounge in a US airport.⁷ The difference is, of course, that going into a smoking lounge is entirely up to you; breathing the air in Beijing, if you live or work there, or happen to be visiting, is not.

While Beijing received most of the attention in January 2013, more than 30 cities and 600 million people over a 1-million-square-mile area were affected. The city of Shijiazhuang, the capital of Hebei, Beijing’s neighboring province, for instance, recorded a reading of more than 1,000 μg/m³.

p. 66↵Expatriates living in China dubbed this smog-blighted air the “airpocalypse,” a term that has stuck and continues to be used when skies in China are especially smoky and registering high PM2.5 levels. Ever since, face masks have become daily apparel for those living and working in Beijing, and elsewhere in the country. The fashion industry has even designed lines of face masks for the style-conscious. Room air purifiers, costing $500 and up, have been hard for dealers to keep on the shelves. Social media sites like Weibo have been filled with advertisements for purifiers and netizens’ questions and comments about how various brands of purifiers compare. Schools competing for students whose families worry about the health effects of the polluted air on their children have invested millions of dollars in constructing domes with hospital-grade filtration systems over their playing fields, the costs of which are reflected in the exorbitant tuition rates.⁸

International corporations have been finding it increasingly challenging to attract foreign recruits to work in Beijing and so offer “hazard pay” or “danger money” of up to 20% or 30%. The American Chamber of Commerce in China, in a March 2014 survey, asked, “Have you or your organization experienced any difficulties in recruiting or retaining senior executives to work because of air quality issues?” Forty-eight percent of the organization’s 365 members said yes.

The airpocalypse is also having an effect on Beijing as a destination for tourists. In the one-year period following the airpocalypse, foreign tourism, with all of its economic benefits, was down 10% to 15% from the previous year.⁹

The airpocalypse of January 2013 was something of a defining moment, transforming daily life in cities like Beijing. Its effect has been lasting. The Chinese people are more aware than ever before of the pollution in their air. And no longer do the national weather media describe the air on days when the smog is heavy as simply wu (霧), “fog.” They now call it what it is: wumai (霧霾) or mai (霾), “smog.”

p. 67How Much Coal Does China Consume, and How Does China Compare to Other Countries?

Industrialization has driven China’s economic development, and this industrialization, in turn, has been powered by coal. Coal today supplies about 64% of China’s total energy consumption (the power sector uses the most, followed by the steel and cement industries), and the tonnage of coal has grown commensurately with the economy over the years. In 2013, the country used an estimated 4 billion tons of coal, almost three times more than it used as recently as 2000. The increase is staggering, as is the absolute amount: China now consumes yearly as much of the rest of the world combined (Figure 5.1).

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Figure 5.1  Coal demand in China and in the rest of the world

It is coal combustion on this scale that accounts for much of the country’s pollution: estimates have it that coal accounts for 50% of the PM2.5 in China’s air and 90% of the sulfur dioxide. A study by Teng Fei at Tsinghua University revealed that in 2012 PM2.5 from coal combustion alone accounted for 670,000 premature Chinese deaths.¹⁰

p. 68↵And then there is the carbon burden. China is the world’s largest emitter of the greenhouse gas CO₂, releasing about 10.5 billion metric tons into the air in 2014. This represents nearly 30% of the world’s emissions, and twice as much as the United States, the next largest emitter.

Recently, however, there has been some positive news. Data from 2014 and 2015 show that for the first time in the 21st century China’s consumption of coal is falling: it decreased in 2014 by 2.9% and in 2015 by another 3.7%. A number of factors may help to explain the decline in coal use: a weakening global economy, the country’s aggressive development and use of other energy sources, the government’s more vigilant enforcement of environmental regulations, the shuttering of small and inefficient coal plants, and the removal of highly polluting vehicles from the roads. As promising as these recent figures are, it is hard to know whether they mark the beginning of a trend, though analysts like Nicholas Stern, Fergus Green, and Ye Qi suggest they do.¹¹

What we can say with certainty is that the Chinese government is eager to reduce its reliance on coal. China’s growing investment in alternative energy resources—wind, solar, hydroelectric, and nuclear—is one strong testament. Perhaps even stronger is the government’s declaration to cap the country’s total energy consumption by 2020 (at 5 billion tons). This is the first-ever talk of a national cap. At the same time, the government has stated its intention to reduce its carbon intensity 60% to 65% below 2005 levels by 2030; to increase the percentage of non-fossil fuels in the total energy mix from 11.2% in 2014 to 15% by 2020, and to 20% by 2030; and, finally, to peak carbon emissions by 2030 at the latest.

Still, given China’s need for enormous amounts of energy to maintain economic growth, the ready availability of coal, and the time it takes to gear up the capacity of other energy resources, the widely held expectation is that coal will remain p. 69↵dominant for the foreseeable future, providing 60% of China’s total energy mix through 2020 and 50% through 2030.

How Do Vehicles Contribute to China’s Air Pollution?

Vehicle exhaust contributes to primary and secondary particulate matter, acid rain, and CO₂ emissions. After coal combustion, vehicle exhaust is the leading cause of PM2.5 pollutants in China. Since vehicles (including passenger cars, light- and heavy-duty vehicles, buses, and motorcycles) are more plentiful in urban areas, it is in urban areas that their emissions have the greatest effect on air quality. One recent study calculated that motor vehicles account for 15% to 35% of the local PM2.5 in Chinese cities. In Beijing the estimate is 31% of the PM2.5, in Shanghai 25%, in Shenzhen 31%, in Chengdu 20%, and in Hangzhou 33%.¹² These figures, however, should not be taken too literally; new studies, with varying figures, appear regularly. Distinguishing the sources of particulate matter (e.g., vehicles, incinerators, coal combustion, construction dust, road dust) is challenging, as it requires chemical analysis of the PM2.5, the methods for which are still improving.¹³

Whatever the precise figures, there is general acknowledgment that the PM 2.5 contribution made by vehicles is dangerously high—and growing. A 2015 United Nations Development Programme (UNDP) brief on China’s air pollution concluded, “Vehicle emissions are now making a larger contribution to air pollution both in the form of direct particulate matter from incomplete combustion (soot, black carbon, etc.) and from NOx [nitrogen oxide] emissions, a precursor for PM2.5.”¹⁴

Especially concerning, in my view, is that idling vehicles emit much higher levels of PM2.5. The Beijing News reported in July 2013 that a freely moving car on Beijing’s West Second Ring Road produces 25 to 30 μg/m³, while a car idling during p. 70↵peak congestion there produces more than three times as much (90–100 μg/m³). Traffic congestion, of course, is already a huge problem in Chinese cities. But consider what the congestion could be like in 2030, when it is estimated that there will be 500 million vehicles on Chinese roads, two to three times the current number (and more than double the number of total vehicles in the United States today). And then consider the possible effects on public health.

As the UNDP brief reminds us, the nitrogen oxide emitted by vehicles during combustion reacts in the air to form particulate matter. But it also reacts in the air to form acid rain—as does the relatively small amount of sulfur dioxide emitted by vehicles. And when acid rain falls, it forms mild solutions of nitric and sulfuric acid, harming waterways and the fish and aquatic life that inhabit them, and polluting the soil, making it difficult for trees and forests to survive. Finally, nitrogen oxide also reacts in the air to form tropospheric ozone, which can damage forests and crops and trigger a range of human health problems, particularly in the lungs and heart.

In 2014, of China’s total carbon emissions—approximately 10 billion tons—roughly 730 million tons were attributable to the road transport sector. Not a small amount! In fact, the CO₂ that China produces from road transport alone is more than what Canada or the United Kingdom emits in total. If, as estimated, the number of vehicles on China’s roads climbs to 500 million within the next decade and a half, the tonnage of CO₂ emissions could balloon to 1.3 billion or more. The potential for this sort of increase in vehicular CO₂ emissions is worrisome for a government intent on reining in air pollution and peaking carbon emissions by 2030.

The central government and municipal governments throughout the country have experimented with a number of measures to reduce the use of vehicles powered by fossil fuelsp. 71↵ (diesel fuel and gasoline) and their polluting emissions. The measures include the following:

In March 2015, the Chinese Ministry of Transport announced a plan to put 200,000 “new-energy” buses and 100,000 “new-energy” taxis on the country’s roads by the end of this decade (in 2014, 15,000 “new-energy” buses were added to the roads).

How Are Smog and Climate Change Linked?

The blanket of sooty air that routinely hangs over much of China, especially the cities, is smog. The pollutants primarily responsible for this smog are PM2.5 and PM10. Once emitted into the air, particulate matters lingers relatively briefly (sometimes as a little as an hour and typically no more than a week or two) as rain, wind, and changing temperatures wash it away, disperse it, or transport it elsewhere.

p. 72↵Greenhouse gases emitted into the air, especially CO₂, but also methane and nitrous oxide, are what make for the warming temperatures associated with climate change. CO₂ is a colorless and odorless gas; it does not directly contribute to smog as particulate matter does, nor does it carry immediate risks to public health. The harm it poses comes from its greenhouse effect. Once released into the atmosphere, it accumulates and remains there for decades, even centuries, trapping the heat released by the planet’s land and oceans and preventing it from passing out of the atmosphere into space. How this warming will ultimately affect humankind and Planet Earth is, of course, a matter of intense debate.

What links smog and climate change is that the particulate matter that spawns the smog and the CO₂ that warms the globe have a common source: fossil fuel combustion. That is, burning coal, oil, or natural gas emits a heavy burden of both particulate matter and CO₂. Thus, when the Chinese government, in waging a war on pollution, puts a limit on coal use; shutters coal-fired power and industrial plants; invests in alternative energy sources; eliminates old, polluting vehicles from the road; institutes higher fuel standards; encourages the purchase of new-energy vehicles; and promises to increase the percentage of non-fossil fuels in the total energy mix, it is at the same time reducing the country’s harmful, planet-warming emissions.

By the same token, when in the lead-up to the 2015 Paris Agreement President Xi and Chinese climate representatives pledged on China’s behalf to reach peak coal use by 2030, to cut CO₂ emissions per unit of GDP (carbon intensity) by 60% or more over 2005 levels by 2030, and to increase the non-fossil fuel share of the total primary energy consumption to 20%, they fully understood that these measures will at the same time “co-benefit” their goal to clean up the country’s air. For them, taking on global climate change in large part addresses the nation’s pollution crisis—and the growing health issues and costs associated with it.

p. 73↵By all accounts, the role China played in Paris in 2015 was far more conciliatory and constructive than the role it played in 2009 in Copenhagen. What had changed? Among other factors, in the intervening years China had become far more invested in facing its environmental challenges. Cooperating on climate change in Paris was, from Beijing’s perspective, entirely consistent with its commitment to address environmental pollution at home. In short, tackling climate change was now viewed to be very much in the country’s interest.