Air pollution is linked to numerous health concerns, from asthma to an increase in the amount and severity of lung and heart disease. The World Health Organization (WHO) considers air pollution a public health issue and their data estimates that 99 percent of the world breathes air with harmful levels of pollutants.
Government regulations are a major tool in improving air quality. A study published February 1 in the journal Environmental Science & Technology finds that stricter clean heating policies put in place by China may have reduced 23,000 premature deaths in 2021 compared to 2015.
China has historically utilized a centralized winter heating strategy that provides free or heavily subsidized heating to cities from about mid-November to March. Biomass burning, or burning wood and other vegetation for warmth, iswas also often used for heating in rural areas. This combination of biomass and coal burning is often associated with haze during China’s winters.
In 2013, China introduced the Air Pollution Prevention and Control Action Plan which accelerated the use of a centralized heating district and encouraged a switch to cleaner fuels. Coal still accounted for 83 percent of total heating in 2016, but the Chinese central government issued its Clean Winter Heating Plan for Northern China the following year.
[Related: Why China just can’t seem to quit coal.]
Between 2015 and 2021, Beijing, Tianjin, and 26 surrounding cities (known as the “2+26” cities) saw concentrations of fine particulate matter (PM2.5) reduced by 41.3 percent. Other northern Chinese that did not enact the same heating policy saw a 13 percent decrease. The team found that the premature deaths from poor air quality fell from 169,016 in 2015 to 145,460 in 2021.
“Our research demonstrates the effectiveness of China’s clean winter heating policies on reducing PM2.5 – with particular success for the stricter clean heating policies in ‘2 + 26’ cities, which also led to a reduced impact of heating emissions on sulfur dioxide (SO2),” said study co-author and atmospheric biogeochemist Zongbo Shi, from the University of Birmingham, in a statement. “These results demonstrate clear air quality benefits from the stricter clean heating policies in ‘2 + 26’ cities.”
According to the study, evaluating the effectiveness of clean heating policies is difficult due to complicated chemical and physical processes in the atmosphere and socioeconomic factors. The team from Nankai University in Tianjin and the University of Birmingham in England used a new method that combined machine learning and a synthetic control method, which evaluates an intervention’s effect.
“Using a novel approach combining machine learning with causal inference, we showed that heating in northern China was a major source of air pollution,” said Shi. “However, clean heating policies have caused the annual PM2.5 in mainland China to reduce significantly between 2015 and 2021, with significant public health benefits.”
Further decarbonizing measures will continue to help clean the air, according to the study.
“Clean heating policies in northern China not only reduced air pollution but also greenhouse gas emissions, contributing to China’s push for carbon neutrality. However, we found that heating remains an important source of air pollution in northern China, particularly in cities that are not part of the ‘2+26’ cluster,” said Robert Elliot, study co-author and applied economist from the University of Birmingham, in a statement. “Decarbonizing heating should remain a key part of China’s carbon neutrality strategy that not only reduces air pollution but also provide[s] significant public health benefits.”
China still has a steep hill to climb to decarbonize as a whole. It aims to hit peak carbon emissions by 2030 and become carbon-neutral by 2060. While it is installing renewable energy rapidly, it still built 33 gigawatts of new coal plants in 2021 and hit a record-breaking 4.07 billion tonnes of coal output that same year.