The U.S. is experiencing a different kind of “reshoring.” China, the world’s largest air polluter, is sending us via the jet stream a fair amount of their harmful emissions. And, according to a recent study published in the Proceedings of the National Academy of Sciences, much of it is our own fault.
Researchers say a large part of the emissions are due to Chinese manufacturers making goods for foreign consumption. For years, American companies have been outsourcing production to China to take advantage of low labor rates. So all the cheap appliances, toys, and electronics we’re hooked on may be coming back to bite us, in an indirect way.
Making many of these products takes a lot of energy. Chinese industry relies on coal as its main source of power, and emissions controls on power plants are often limited or outdated. Further, the general level of manufacturing technology and energy-efficiency standards in particular aren’t as advanced as in the west, so it takes even more energy to make these goods in China.
The study says 36% of the sulfur dioxide, 27% of nitrogen oxides, 22% of CO, and 17% of soot emitted in China are due to production of goods for export. About a fifth of those pollutants were attributed to goods headed to the U.S.
Atmospheric models used by the researchers indicate that this accounted for a quarter of the sulfate pollution over the western U.S. in 2006, and increased surface sulfate concentrations by up to 10% and ozone by 1.5%.
According to the U.S. EPA, scientific evidence links short-term exposure to high levels of sulfur oxides with an array of adverse respiratory effects, including bronchoconstriction and increased asthma symptoms, particularly in children and the elderly. Longer term, it can cause or worsen respiratory diseases such as emphysema and bronchitis, and can aggravate heart disease.
A second NAS study claims computer models show that pollution from Asia, particularly fine aerosols, could be intensifying Pacific storms headed to the U.S. and altering weather patterns over North America.
Simulations showed that aerosols alter the distribution of moisture and heat in the Pacific storm track, a relatively narrow zone where cyclones form and travel and a major driver of weather in the Northern Hemisphere. These tiny particles suspended in the air can change weather patterns because they scatter or absorb solar radiation; and water vapor condenses around aerosols, a process that alters cloud formation and makes them denser and higher. The results, according to the model, are more precipitation, stronger cyclones, and more heat moving from the tropics toward the arctic.
Researchers didn’t predict how this affects U.S. weather, so we have to cross our fingers that it doesn’t exacerbate the Southwest drought or Midwest storms.
What is pretty clear is that air pollution in China isn’t a regional problem. Thanks partly to outsourcing, what we save in cheap goods we’re paying for in lower air quality and, possibly, worse weather.