Chinese air pollution blowing across the Pacific
Ocean is often caused by the manufacturing of goods for export to the US and
Europe, according to findings by Chinese and international researchers published
Monday in the Proceedings of
the National Academy of Sciences. It's estimated that about 20% of the
pollution that enters China's atmosphere comes from these exports.
The study is the first to quantify how much of
the pollution reaching the American West Coast is from the production in China
of cellphones, televisions and other consumer items imported here and elsewhere.
“We’ve outsourced our manufacturing and much of
our pollution, but some of it is blowing back across the Pacific to haunt us,”
said Steve Davis, a co-author. “Given the complaints about how Chinese
pollution is corrupting other countries’ air, this paper shows that there may be
plenty of blame to go around.”
Los Angeles experiences at least one extra day a
year of smog that exceeds federal ozone limits because of nitrogen oxides and
carbon monoxide emitted by Chinese factories making goods for export, the
analysis found. On other days, as much as a quarter of the sulfate pollution on
the U.S. West Coast is tied to Chinese exports. All the contaminants tracked in
the study are key ingredients in unhealthy smog and soot.
China is not responsible for the lion’s share of
pollution in the US. Cars, trucks and refineries pump out far more. But powerful
global winds known as “westerlies” can push airborne chemicals across the ocean
in days, particularly during the spring, causing dangerous spikes in
contaminants. Dust, ozone and carbon can accumulate in valleys and basins in
California and other Western states.
Davis says black carbon is a particular problem:
Rain doesn’t easily wash it out of the atmosphere, so it persists across long
distances. Like other air pollutants, it’s been linked to a litany of health
problems, from increased asthma to cancer, emphysema, and heart and lung
The study authors suggest the findings could be
used to more effectively negotiate clean-air treaties. China’s huge ramp-up of
industrial activity in recent years, combined with poor pollution controls, has
unleashed often fierce international debates.
“When you buy a product at Wal-Mart,” noted
Davis, an assistant professor a the University of California (UC) Irvine.
“it has to be manufactured somewhere. The product doesn’t contain the pollution,
but creating it caused the pollution.”
He and his fellow researchers conclude:
“International cooperation to reduce transboundary transport of air pollution
must confront the question of who is responsible for emissions in one country
during production of goods to support consumption in another.”
Jintai Lin of Beijing’s Peking
University is the paper’s lead author. Others are Da Pan, also of Peking
University; Qiang Zhang, Kebin He and Can Wang of Beijing’s Tsinghua University;
David Streets of Argonne National Laboratory; Donald Wuebbles of the University
of Illinois at Urbana-Champaign; and Dabo Guan of the University of Leeds in
|Jintai Lin, a professor at Beijing’s Peking University |
Exports accounted for 24.1% of China’s gross
domestic product (GDP) in 2013, down from a peak of 35% in 2007,
before the global financial crisis began to weaken overseas demand even as
China’s domestic economy continued to grow. The 2013 data takes into account
economic data that was released on Monday.
Check out our
, at a low annual charge of €25