Last summer, Xu Demin struggled to cut emissions from his coal-fired factories as part of China’s all-out effort to clean the air for the Beijing Olympics.
He could have simply waited six months. This spring, overseas demand for his farming and construction machinery plummeted, forcing him to close two plants and lay off 300 workers.
The global economic slowdown is helping to accomplish what some in China’s leadership have striven to do for years: rein in the insatiable demand for coal-powered energy that has fed the country’s breakneck growth but turned it into one of the world’s most polluted countries.
Beijing, China’s normally smog-choked capital, is breathing some of its cleanest air in nearly a decade, as pollution-control efforts get a sizable boost from a slowing economy.
“It’s like the sky I saw overseas. I can see clouds. I’ve seen days here like I’ve seen in Europe or the US,” Xu said, his voice echoing in the cavernous space of his idle factory outside Beijing.
In the second half of last year, a period that included the Olympics in August, Beijing recorded its lowest air pollution readings since 2000, data from the Ministry of Environmental Protection showed.
The average monthly air pollution index was 74, about 25 percent lower than the previous seven years. Earlier data were not available.
Experts see several reasons for the improvement, including the relocation of some of Beijing’s dirtiest factories outside the city and the partial continuation of traffic limits imposed for the Olympics.
Perhaps most significant has been the economic downturn. Even elsewhere in China, where no Olympic pollution measures were imposed, the level of dirty air is down.
For now, the cleaner air is a vindication of sorts for Beijing.
Air pollution, while not as low as in August and September when the harshest restrictions were in place, has remained far below recent years. From October through February, the average monthly pollution index was 82.
It’s not just Beijing. Southern China, home to many of the country’s export-producing factories, has seen clear improvement.
Many cities in Guangdong Province, where 62,400 businesses closed last year, have seen a drop in the number of badly polluted days, data on the Guangdong Provincial Environmental Protection Bureau Web site showed.
For example, the factory city of Dongguan reported more than a dozen days in the first half of last year when the air pollution index topped 100, a level considered unhealthy for sensitive groups including infants and the elderly. But in the second half of the year, there were only two such days.
Not all cities saw improvements. But across a sampling of seven key cities, the average number of badly polluted days halved between the first and second half of last year.
A similar phenomenon was seen when the Soviet Union collapsed, causing the industrial haze over the Arctic to drop by nearly 50 percent, said Kenneth Rahn, an atmospheric chemist from the University of Rhode Island who has studied air quality in China.
“In principle, a reduction in economic activity can and will reduce air pollution,” he wrote in an e-mail response. “I would expect something similar for China but of lesser magnitude.”
During boom times, demand for electricity was so high in Guangdong’s Pearl River Delta that companies often endured rotating blackouts. Some installed their own generators, which burned low-grade, dirty fuel.