Air pollution data in China may have been manipulated by local officials, according to a new study conducted by Harvard and Boston University researchers.
The analysis, published Wednesday, found statistically significant differences between data from monitoring stations run by local Chinese officials in five cities – Beijing, Shenyang, Shanghai, Guangzhou and Chengdu – and readings collected by U.S. embassies.
Harvard University’s Jesse Turiel and Boston University’s Robert Kaufmann examined the measurement of PM2.5, a particle matter that’s linked to lung cancer, asthma and heart disease, recorded by Chinese and U.S. stations between January 2015 and June 2017. They discovered temporary divergences between the two data sets that were more likely to occur during periods of high air pollution, suggesting that “government-controlled stations systematically underreport pollution levels when local air quality is poor.”
The report comes amid an announcement Wednesday – Earth Day – that Chinese President Xi Jinping will take part in President Biden’s climate summit this week. Xi will participate in the online event and “deliver an important speech” from Beijing, the government-run Xinhua News Agency said.
China is the world’s largest carbon producer, closely followed by the U.S.
Beijing faced a public outcry in 2012 over official government readings that critics said drastically underestimated the severity of the pollution problem. The nation’s capital committed to publishing hourly air quality reports based on PM2.5, which are 2.5 microns in diameter and are considered to be among the most harmful health risks posed by pollution. Previously, China’s Ministry of Environmental Protection only published air quality data that measured particles up to 10 microns in diameter, allowing it to obscure the real picture of the country’s air problems.
But despite the pledged changes – including requiring cities to report hourly pollution concentrations rather than daily averages – the latest report suggests that officials are still misreporting the data “just in different, more difficult-to-detect forms,” Turiel and Kaufmann wrote. Rather than manipulating the data around a certain threshold, officials are more likely to understate pollution during periods when concentrations are high.
That’s in part because local officials are incentivized to underreport in order to avoid professional repercussions, the authors argued. For instance, the Chinese Community Party has increased the penalties for local officials in failing cities, without also providing more government resources or financial support, leading to difficult attainment targets and a persistent lack of resources.
“Local bureaucrats face immense pressure to report the ‘correct’ numbers to their higher-ups, and some resort to colluding with other local officials or misreporting data,” they wrote. “Given these institutional incentives to cheat, official air pollution data in China often is treated with a high degree of skepticism, by both outside observers and the general public.”