Poor air quality in China isn’t a surprise to anyone who’s read the news in the last few years. As China has become a globalized, urbanized powerhouse, its air pollution has grown in proportion to its prosperity.
At its worst, air quality has reached emergency conditions, threatening the health of tens of millions of people.1 At its best, China’s poor air quality dissipates temporarily, especially in anticipation of major events like the 2008 Beijing Olympics or national government meetings.2,3
But what you don’t know about China’s air quality might surprise you. Most of us just hear breaking news about major metropolitan areas like Beijing, but the problems (and solutions) reach far beyond China’s city limits. Its urban population represents only 56% of the country’s population and only a fraction of the country’s stories about air pollution.4
Growing numbers of vehicles and factories are fueled by coal and are the primary sources of the country’s dangerously high levels of air pollution.5
Although coal-related pollution has historically been a perennial air quality issue in China as a whole, coal burning during cold months causes levels of airborne pollutants to rise drastically. According to one study, 40% of the PM2.5 (particulate matter smaller than 2.5 microns) in China’s atmosphere can be attributed to both industrial and residential sources of coal burning.6
This same study also found that nearly half a million deaths in the country were related to PM2.5 exposure from a combination of coal burning at power plants, factories, and homes burning coal for heat and fuel.
Fortunately, coal-related pollution drops to almost negligible levels once the cold seasons end. A 2015 study found that PM2.5 levels related to coal burning, especially in heavily populated regions like Beijing, see enormous drops due to decreased use of indoor coal and biomass fuel burning for heat in homes throughout these cities.7
Beijing’s pollution is often worsened by the surrounding mountains. Because the mountains form a natural barrier on all sides, pollutants collect quickly because they can’t be dispersed as easily via wind and other climatic processes that normally clear the air of pollutants in less rugged regions.8
Also, during the winter, much of Beijing’s pollution is trapped in the lower atmosphere by temperature inversions. Inversions happen when warm air high in the atmosphere confines cold air in the lower atmosphere, preventing pollutants from naturally rising to high altitudes away from the air that people breathe at ground-level.9
Combine mountains and wintertime inversions with increased coal burning during cold weather, and you’ve got a crucible for hazardous air quality for months at a time.
Plenty of research shows that airborne pollutants originating in China often ride global wind currents, affecting air quality in the United States and beyond in the Western Hemisphere.10,11,12 Air pollution can’t always be predicted with quite as much accuracy as the weather can be (although air pollution forecasting methods have begun to improve significantly), so these regions are largely unable to foresee and prepare for influxes of air pollution.
But a 2018 study in the Journal of Environmental Management measured pollutant levels at several sites in the western United States over a 13-year period and pinpointed one consistent, major source of particulate pollutants: sandstorms.13
Enormous sandstorms regularly occur during the spring and summer, encompassing many Chinese cities in a toxic yellow haze and inflating levels of particulate pollutants even in the western U.S. by up to 39%.
Sandstorms are well-documented in much of China. Dry land resulting from soil erosion comprises almost 30% of the country’s total area, and “desertification,” caused by the mass clearing of grasslands and forests, creates ample opportunities for megastorms to erupt.14,15
But these storms happen due to relatively predictable seasonal weather patterns, so the study suggests that U.S. policymakers could observe these dust storms and better prepare for the inevitable impact they have on U.S. pollution levels.
As China’s dust storms illustrate, soil erosion where plants and trees have been leveled contributes to air pollution not only in China but in far-flung places around the globe. Between massive amounts of dust particulates during the hot months, with increases in coal emissions during the cold months, China and all the countries in the path of the pollutants that travel around the world rarely get a break for clean air.
But now, an international team of agricultural researchers thinks they have a solution: grass.
Switchgrass, that is.16
A 2017 report from a team of international researchers in China and the U.S. believe that the solution to “desertification” is “revegetation.” This refers to the process of restoring dry, barren, or damaged land by introducing plants and other life back to the soil. Revegetation with switchgrass would allow seeds to take root and create a new cycle of life that could make even the most desertified ecosystem in China, such as the nearly 250,000 square-mile (640,000 square-kilometer) Loess Plateau, fertile again.
And using switchgrass could potentially solve two major pollution problems in China (and elsewhere).
Switchgrass can not only help stabilize the soil but also be harvested and burned for heat and fuel as a far cleaner biomass crop than coal. Switchgrass provides enormous possible incentives for farmers who could grow the grass during farming seasons and sell harvested grass for fuel during the winter.
Over the last few years, as China becomes an increasingly important player on the world stage, a series of high-profile, emergency-level air quality conditions spurred China to take the lead in the world’s commitment to clean energy, especially as other major economic powers have taken a back seat to global sustainability leadership.
In 2014, a report from the Pew Charitable Trusts found that China led the world in clean energy investments, attracting a $54.2 billion market to its energy sector and investing a total of $53.3 billion in wind and solar power to reduce its dependence on coal power in the long term.17
To combat pollution caused by coal, the city of Beijing also introduced bans on coal for indoor heating as early as 2014, urging citizens to use natural gas and other clean energy sources with the goal of eliminating coal sale and use entirely by 2020.18
So far, the ban has been moderately successful – the coal ban was reversed temporarily during a heating crisis in late 2017 because of a perfect storm of coal scarcity and high demand for alternative (and often more expensive) fuel sources. But overall, Beijing has experienced more days of clean air and blue skies.19 And with China’s commitment to renewable energy, this will, of course, result in even bluer skies.
It’s clear that even when a country makes strides in helping mitigate the sources and effects of air pollution, it still has limited power over the weather, winds, and the consequences of thousands of years of farming and grazing.
So here are a few tips for keeping your lungs clean on your next trip to China:
With its recent investments in air purification and alternative biomass fuels, China may not make pollution headlines forever. But seeing a wide range of science and solutions being applied to China’s air quality problems provides many unprecedented opportunities to learn how air quality can be improved on a massive scale.
