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Air pollution stretches from Beijing to Shanghai, as seen from space

The views expressed are those of the author and are not necessarily those of Scientific American.

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NASA’s Terra satellite captured this image of a long belt of smog stretching from Beijing (in the upper third of the image) to Shanghai (in the bottom right corner). That distance is roughly 1,200 km or about the distance from Boston, MA to Raleigh, NC. While smog and air pollution is fairly routine, it is less common to see smog stretch so far south.


Air pollution shows up as dark gray in this image from December 7, 2013. Clouds and fog appear as white. Credit: NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response

In addition to ground-level ozone (smog), measurements taken at U.S. embassies in Beijing and Shanghai recorded elevated levels of particulate matter (soot) fewer than 2.5 microns in diameter (via Earth Observatory):

ground-based sensors at U.S. embassies in Beijing and Shanghai reported PM2.5 measurements as high as 480 and 355 micrograms per cubic meter of air respectively. The World Health Organization considers PM2.5 levels to be safe when they are below 25.

Fine, airborne particulate matter (PM) smaller than 2.5 microns (about one thirtieth the width of a human hair) is considered dangerous because it is small enough to enter the passages of the human lungs. Most PM2.5 aerosol particles come from the burning of fossil fuels and of biomass (wood fires and agricultural burning).

At the time of the satellite image, the air quality index (AQI) reached 487 in Beijing and 404 in Shanghai. An AQI above 300 is considered hazardous to all humans, not just those with heart or lung ailments. AQI below 50 is considered good.

Smog and particulate matter tend to form due to problems during combustion. Uneven temperatures in a flame can lead to formation of pollutants like nitrogen oxides (NOx) that lead to smog, and particulate matter (or soot, unburned bits of fuel). These pollutants can be captured by cleaning the exhaust gas from a power plant (or industrial boiler), usually by recirculating exhaust gas back in to burn up any remaining fuel, or by passing it through a chemical process that strips out nitrogen oxides (using ammonia and a catalyst). These methods can be expensive and consume large amounts of energy, so operators tend to shy away from them. Instead, some power plants or factories will shut down completely to avoid producing air pollution.

Other space shots of Chinese pollution can be seen in “Smog shuts down Harbin, China”“Beijing’s air pollution as seen from space” and “China enveloped in smog, as seen from space. Again”.

David Wogan About the Author: An engineer and policy researcher who writes about energy, technology, and policy - and everything in between. Based in Austin, Texas. Comments? Follow on Twitter @davidwogan.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. tuned 3:11 pm 12/10/2013

    Kinda hard for the Fossil Fuel lobbyists to argue with direct evidence, so they don’t show up at all.

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  2. 2. Chryses 5:55 pm 12/10/2013

    The successful Chinese dash for prosperity has had at least one unwanted consequence.

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  3. 3. Vaing1984 8:00 pm 12/10/2013

    My last pay check was $9500 working 12 hours a week online. My sisters friend has been averaging 15k for months now and she works about 20 hours a week. I can’t believe how easy it was once I tried it out. This is what I do,,,,,Rush64.COM

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  4. 4. Uncle.Al 8:54 pm 12/10/2013
    All your pollutions are belong to us.

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  5. 5. Devonshire 11:05 pm 12/10/2013

    “Can you think of any problem in any area of human endeavor on any scale, from microscopic to global, whose long-term solution is in any demonstrable way aided, assisted or advanced by further increases in population, locally, nationally, or globally?”

    The now late Professor Emeritus in Nuclear Physics at the University of Colorado, Al Bartlett (1923-2013)

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  6. 6. Owl905 3:16 am 12/11/2013

    Asian Brown Cloud (ABC), has been a major player in the biosphere for a generation. China was expanding coal-dependence, after the science was known and understood, at the rate of two new power-plants … a month. They’re now the #1 polluter on the planet – after coming from a position of economic takeoff with tactical and strategic alternatives. The new ‘workshop of the world’ is also the main driver on the road to Garbage Dump Earth.

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  7. 7. KENNETH LANE 7:20 am 12/11/2013

    I saw this smog cloud over our home city of St. Louis Missouri back in the 60′s———–while flying back from the west coast. I have seen this smog print many times over most US cities–so what’s news now was “nothing to see here, move along”, 50 years ago.

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  8. 8. hkraznodar 5:57 pm 12/17/2013

    Is this the unspoken companion policy to the 1 child policy intended to get Chinese population under control? Concentrate millions into cities and then kill them with smog. Diabolical!

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