News

Hell with the Lid Taken Off

During the first half of the twentieth century, coal burning at power plants, factories, and homes filled the air over the Midwestern U.S. with pollution. “Smoke”—as air pollution was usually called—used to occasionally block so much sunlight that people were forced to carry lamps in the middle of the day.

Before and After: US East Coast 2005-2011

Pollution builds up along the U.S. East Coast as it passes from one city to the next, particularly in the Northeast Corridor. These cities include Richmond, Washington, Baltimore, Philadelphia, New York City, Boston and all the smaller cities in between. Some of the largest absolute changes in nitrogen dioxide have occurred in this corridor.

Image showing Air Quality in the Ohio Valley, 2005.

Image showing Air Quality in the Ohio Valley, 2011.

Before and After: Ohio Valley 2005-2011

The impact of technology to reduce emissions of nitrogen dioxide and sulfur dioxide from coal-fired power plants is apparent in satellite imagery, which shows the signal of pollution blink out over time. Still, while air quality is improving, power plant emissions of carbon dioxide – a greenhouse gas – remain an issue.

United States Air Quality Improvement, 2005-2011

Nitrogen dioxide pollution, averaged yearly from 2005-2011, has decreased across the United States.
Image Credit: NASA Goddard's Scientific Visualization Studio/T. Schindler.

Air pollution: Are Indian cities better off than the West?

A NASA study finds low levels of a major pollutant over Indian cities. But the window of opportunity is closing fast (Hindustan times/livemint).

Image Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, at NASA GSFC.