A new visualization from NASA illustrates a rare piece of good news about our environment’s health: air pollution levels in major U.S. cities have significantly decreased from 2005 to 2011.
The Ozone Monitoring Instrument (OMI) on NASA’s Aura Satellite has been orbiting the planet for 10 years now. With its ability to distinguish between aerosol types, like smoke, dust, and sulfates, the OMI gives earthbound scientists a space-based view of where and when air pollution occurs.
NASA’s Scientific Visualization Studio has synthesized a decade of OMI’s data on nitrogen dioxide, a nasty yellow-brown gas that gives humans breathing problems, contributes to acid rain, and disturbs ecosystems. (It’s produced mainly by vehicles burning gasoline and by coal power plants.)
This simple, but powerful, animated map shows we’re breathing far less nitrogen dioxide than we were in 2005. Higher concentrations of the gas are visualized by infection-like splotches of orange and red on the U.S. map. Cleaner air is denoted by blue and green.
Individual cities’ pollution report cards vary: New York City saw a 32% decrease in nitrogen dioxide. Atlanta, which has helped purify its air with emission-control devices on power plants, saw a 42% decrease. Denver cleaned up by 22%. What accounts for these improvements in the face of growing populations and more cars on the roads? Better environmental regulations and technological advancements like smart cars and emission control devices like those used in Atlanta, NASA says.
But these improvements don't mean we can all relax and go back to driving Hummers. About 142 million people still lived in areas in the United States with unhealthy levels of air pollution, according to the EPA. Despite their sunny skies, Los Angeles, Phoenix, and Visalia-Porterville, California, are in a three-way tie for the second most polluted city in the U.S. They're out-polluted by Bakersfield-Delano, California, which took first place. Hopefully, these cities will clean up their acts in time for the next pollution report card.