It's a common misconception that the Great Wall of China can be seen from space, but there is another manmade object close by that is visible from 438 miles up -- a soupy mass of smog hovering over Beijing so thickly opaque that it can actually obscure a large swath of the city from sight. Just days ago, NASA's Aqua satellite returned this image of the North China Plain during its recent chockingly intense bout of air pollution, which reduced on the ground visibility to a mere 200 meters, underscoring China's significant contributions to global carbon emissions.
For comparison, here's the same region on a clear day.
On January 10, the Aqua satellite, outfitted with NASA's climate-monitoring Moderate Resolution Imaging Spectroradiometer (MODIS), turned to the North China Plain; what it found was darn right ghastly, says NASA:
One major constituent of haze is particle pollution, such as dust, liquid drops, and soot from burning fuel or coal. Particles smaller than 10 micrometers (called PM 10) are small enough to enter the lungs, where they can cause respiratory problems. The density of PM10 reached 560 micrograms per cubic meter of air on January 10, said the Beijing Environment Protection Bureau. By contrast, U.S. cities exceed air quality standards when PM10 concentrations reach 150 micrograms per cubic meter.
But most of the pollution that makes up haze isn’t PM10; it’s finer particles, smaller than 2.5 micrometers in diameter (PM2.5). These particles can embed themselves deep in the lungs and occasionally enter the blood stream.
As if the health effects of such pollution on the Chinese population alone were not enough to cause concern from such a massive cloud of smog, this day's picture of pollution is but a snapshot of a long-term problem wherein excessive carbon emissions threaten the health of the world as a whole. Not surprisingly, those living in Beijing have already begun to raise concerns over their freakishly bad air pollution -- which last week forced the cancelation of dozens of flights -- but such a sight should really concern us all.
Unlike the Great Wall of China, the Great Smog of China is not affixed to any foundation. Instead, it promises to drift around the globe and dispense throughout the atmosphere, tipping the fragil balance of our global climate a bit closure to irreparable peril.
And also unlike the Great Wall, its builders haven't finished.