North America polluted by East Asia?
In a recently released study, NASA researchers have confirmed that air pollution travels around the world. They've used new satellite sensor capabilities to measure pollution traveling from East Asia to North America between 2002 and 2005. According to NASA, the amount of pollution arriving in North America is equivalent to about 15 percent of local emissions of the U.S. and Canada. This study is interesting, but seriously biased. First, it doesn't measure pollution coming from Europe. And even more important, where are going the pollutants created in North America? But read more...
You can see above a world map showing how the huge amounts of dust generated by the East Asian fires of 2003 have moved over the Pacific Ocean (Credit: NASA/Goddard Space Flight Center) You'll find a larger version of this map on this page at NASA.
Now, let's look at the researchers' findings. "'We used the latest satellite capabilities to distinguish industrial pollution and smoke from dust transported to the western regions of North America from East Asia. Looking at four years of data from 2002 to 2005 we estimated the amount of pollution arriving in North America to be equivalent to about 15 percent of local emissions of the U.S. and Canada,' said Hongbin Yu, an associate research scientist of the University of Maryland Baltimore County working at NASA's Goddard Space Flight Center. 'This is a significant percentage at a time when the U.S. is trying to decrease pollution emissions to boost overall air quality. This means that any reduction in our emissions may be offset by the pollution aerosols coming from East Asia and other regions.'"
These measurements have been done with the help of the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Terra satellite. What are the results? "Yu and his colleagues measured the trans-Pacific flow of pollution in teragrams, a unit of measurement of the mass of pollution aerosol (1 teragram is about 2.2 billion pounds). Satellite data confirmed 18 teragrams -- almost 40 billion pounds -- of pollution aerosol was exported to the northwestern Pacific Ocean and 4.5 teragrams -- nearly 10 billion pounds -- reached North America annually from East Asia over the study period."
This research work has been published in the American Geophysical Union (AGU)'s Journal of Geophysical Research (Atmospheres) under the title "A satellite-based assessment of transpacific transport of pollution aerosol." There is no way to purchase the article, but here is a link to a PDF document available to AGU members.
Finally, while I was preparing this post, I found that Technology Review has just released an article by Brittany Sauser on the same subject, "Measuring Asia's Pollution Exports." Please read this well-written article which also gives you an easy access to a 48-second streaming video showing "the transport of particulate pollution across the North Pacific in 2003, as observed by the moderate resolution imaging spectroradiometer (MODIS) onboard the Terra satellite."
Sources: NASA/Goddard Space Flight Center news release, March 17, 2008; and various websites
You'll find related stories by following the links below.