Air Pollution In China: Understanding The Complex Causes

Air pollution is a pressing issue in China, causing an estimated 1.24 million premature deaths in 2017 alone. The country's rapid industrialization, population growth, and economic boom have led to a significant increase in emissions, particularly from the burning of fossil fuels, vehicle engines, and manufacturing. China's air pollution has severe health, social, and economic repercussions, threatening not only the Chinese public but also global health and the world economy. With international trade redistributing emissions, China's air pollution extends beyond its borders, impacting air quality in other countries, including the United States.

Industrialisation and manufacturing

China's rapid industrialization and manufacturing processes have significantly contributed to its air pollution crisis. The country's economic growth has been largely driven by the use of coal, a cheap but highly polluting source of energy. While the percentage of energy consumption from coal has decreased over the years, it still accounted for 57.7% in 2019. As a result, large coal-powered industries have become key drivers of China's air pollution and economic development.

Six high-pollution industries are the main sources of airborne pollutants in China, according to the Environmental Statistics Yearbook of China from 2011 to 2015. These include oil processing, coking, and nuclear fuel processing; chemical raw materials and chemical products manufacturing; non-metallic mineral production; ferrous and non-ferrous metal smelting and rolling processing; and electricity and heat production and supply. Together, these six industries account for almost 90% of all industry-related emissions.

The steel industry, in particular, has emerged as China's biggest polluter since 2017, surpassing electricity generation. Additionally, the production of goods for foreign consumption, particularly exports to the United States, has contributed to increased air pollution in China. The manufacturing of these goods has been associated with significant emissions of sulfur dioxide, nitrogen oxides, carbon monoxide, and black carbon.

China's industrialization and manufacturing activities have also led to the unsafe release of mercury into the environment. Coal-burning power plants, both domestically and those financed and operated by Chinese companies in other countries, have made China the world's greatest emitter of mercury air pollution. This neurotoxin poses a significant threat to public health and the environment.

Furthermore, China's industrializing and manufacturing sectors face challenges in regulating polluting emissions. Enterprises in these sectors are the most significant sources of air pollution and are difficult to regulate due to the complex interplay between economic growth and environmental protection. The Chinese government has implemented policies to mitigate air pollution, but the priority given to economic development over the years has resulted in neglected industrial pollution mitigations in certain regions.

Population growth

China is the world's most populous country, with 1.4 billion people as of 2019, accounting for 18.4% of the global population. Its rapid population increase, rapid economic growth, and lax environmental oversight have resulted in increased water demand and pollution.

The immense urban growth of Chinese cities has substantially increased the need for consumer goods, vehicles, and energy. This, in turn, increases the burning of fossil fuels, resulting in smog. A study from 2012 showed that fine particles in the air, which cause respiratory and cardiovascular diseases, were one of the key pollutants that accounted for a large fraction of damage to the health of Chinese citizens.

The total number of vehicles in China reached 360 million in 2020, making them a major culprit of air pollution. This is particularly true in larger cities, where the concentration of exhaust from vehicles is much higher. According to China's Ministry of Ecology and Environment, vehicle emissions were to blame for about 45% of Beijing's air pollution in 2018 and nearly 30% of the air pollution in Shanghai.

China's past economic growth has substantially relied on fossil fuels, causing serious air pollution issues. Decoupling economic growth and pollution has become the focus of developing ecological civilization in China. China's leaders have responded with measures designed to improve air quality, but they face significant challenges in balancing economic growth with environmental and social welfare.

Vehicle emissions

Motor vehicle emissions are responsible for a significant increase in CO and NOx concentrations in China. Studies have shown that vehicle emissions contribute approximately 12-36% of total NOx and 10.7% of total PM10 in China. The high levels of NOx and PM emitted by diesel vehicles, which make up only 9.1% of the total vehicles in use, are particularly concerning. The large number of on-road vehicles consumed 95 million tons of gasoline and 172 million tons of diesel in 2013, and this number is predicted to continue rising with increasing car sales.

To address the issue of vehicle emissions and air pollution, the Chinese government has implemented vehicular emission reduction measures since 1995. Researchers have found that despite the huge increase in the number of motor vehicles, vehicular emission control methods have effectively reduced air pollution. The implementation of stricter emission standards, such as CHINA-IV and CHINA-VI, has been important in reducing vehicular emissions, and earlier introduction of such standards would have resulted in even greater benefits. However, there is a stalemate between the rapid development of the vehicle industry and delayed vehicle emission control, and understanding the barriers in the vehicle industry is necessary for developing effective and sustainable measures to manage vehicle-induced air pollution.

Coal power plants

China has become the top power producer globally, with the largest share of global power generation from 2010 to 2018. The majority of China's power generation comes from thermal power plants that combust coal, oil, natural gas, biomass, or other fossil energy. As a result, China's thermal power plants, particularly coal-fired power plants, have become major sources of air pollutants.

From 2010 to 2017, these power plants emitted 5.0–23.5% of China's anthropogenic particulate matter (PM), 15.7–38.7% of its sulphur dioxide (SO2), and 19.1–51.5% of its nitrogen oxides (NOx). These air pollutants contribute to the country's poor air quality, with PM2.5 levels exceeding the World Health Organization's standard of 5 micrograms per cubic meter.

Coal-fired power plants have been identified as a major contributor to air pollution in China. For instance, in 2017, northern China experienced one of its worst episodes of air pollution, with coal estimated to have caused about 40% of the smog in Beijing. The high levels of air pollution led to public outcry, with citizens taking to social media to demand that the government take action to protect the country's children.

The Chinese government has imposed strict policies on coal-fired power plants and made efforts to transition to cleaner energy sources. For example, Beijing closed the last four coal-fired power and heating plants in its municipal area in 2019, replacing them with gas-fired power plants. However, China's dependence on coal for its economic growth and energy needs remains a challenge. Coal provides 70% of the country's energy, and while the government has invested in renewable energy, it has also approved the construction of 200 new coal power plants.

The early 2020 COVID-19 outbreak provided further evidence of the impact of coal-fired power plants on air pollution. During the strict lockdowns, most cities in China suspended commercial and industrial operations and banned transportation. This cessation of economic activities was expected to result in a significant decrease in air pollution levels. However, the daily concentrations of PM2.5, SO2, and NOx remained relatively high, indicating that the continued operations of coal-fired power plants contributed significantly to air pollution during this period.

Household solid fuel usage

China's rapid industrialization has led to intense levels of air pollution, which presents serious social, economic, and political problems. One of the major contributors to air pollution in China is household solid fuel usage. Solid fuels refer to biomass (mainly wood and crop residues) and coal fuels that are burned for cooking and heating.

In 2003, approximately 80% of the energy consumed by rural households was in the form of biomass, and almost 10% was coal. While China's urbanization has led to a decrease in solid fuel usage, over 60% of the population still lives in rural areas and relies on these fuels. This means that nearly all rural residents and a shrinking fraction of urban residents use solid fuels for household needs. As a result, indoor air pollution from solid fuel use in China is responsible for approximately 420,000 premature deaths annually, exceeding the number of deaths attributed to urban outdoor air pollution.

The combustion of solid fuels produces high levels of particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide, which are harmful to human health. The World Health Organization (WHO) has estimated that solid fuels used in Chinese households cause approximately 420,000 premature deaths annually, with observed health effects including respiratory illnesses, lung cancer, chronic obstructive pulmonary disease, weakening of the immune system, and reduction in lung function.

The Chinese government has recognized the issue and targeted the burning of solid fuels by households in heavily polluted provinces. In 2018, the government announced a plan to replace coal-burning heaters with natural gas and electric heating systems in 1.2 million homes across 11 cities. However, due to a short supply of natural gas, this policy was reversed in 2019, highlighting the challenges in implementing new policies and balancing economic growth with environmental and social welfare.

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