Help us raise $20,000 to celebrate 20 years. For a limited time, your donation is matched!Donate

The Works

NASA Images Capture How Air Has Gotten Cleaner in 6 Cities

Satellite data from NASA indicates that the air in major U.S. cities now contains less harmful nitrogen dioxide than in 2005.

Chicago has seen the sharpest reduction in nitrogen dioxide levels. The image shows how nitrogen dioxide concentrations during spring and summer months, averaged from 2005-2007 (left), compare to the average from 2009-2011 (right). (Credit: NASA)

This is your first of three free stories this month. Become a free or sustaining member to read unlimited articles, webinars and ebooks.

Become A Member

Finally, there is some hopeful environmental news to share!

New satellite images recently released by NASA show that air pollution is on the decline in some of the largest U.S. cities. In particular, levels of nitrogen dioxide — a brownish gas linked to respiratory problems — have dropped significantly since 2005, the agency’s scientists say. The gas is produced by gasoline combustion in cars and burning natural gas in power plants. Its decrease at a time when more people are consuming energy and driving cars can be seen as a victory for the Environmental Protection Agency and other agencies that enforce clean air regulations. The progress also indicates that new clean air technologies are helping us shrink our environmental footprint. Still, NASA scientists warn that its still far too soon to begin taking strolls under your local smoke stacks.

“While our air quality has certainly improved over the last few decades, there is still work to do — ozone and particulate matter are still problems,” said Bryan Duncan, an atmospheric scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland in a published statement. And while air quality may be improving, power plant emissions of carbon dioxide — a greenhouse gas — remain an unmitigated threat.

Orange and red areas denote high concentrations and blue and green denote lower concentrations of nitrogen dioxide. (Credit: NASA’s Scientific Visualization Studio, using data from atmospheric scientists Yasuko Yoshida, Lok Lamsal, and Bryan Duncan.)

Click through a slide show of images showing the change in nitrogen dioxide levels in Chicago, Houston, Los Angeles, Atlanta, New York and Denver.

Gallery: Air Pollution

The Works is made possible with the support of the Surdna Foundation.

Like what you’re reading? Get a browser notification whenever we post a new story. You’re signed-up for browser notifications of new stories. No longer want to be notified? Unsubscribe.

Tags: pollutionair quality

Next City App Never Miss A StoryDownload our app ×

You've reached your monthly limit of three free stories.

This is not a paywall. Become a free or sustaining member to continue reading.

  • Read unlimited stories each month
  • Our email newsletter
  • Webinars and ebooks in one click
  • Our Solutions of the Year magazine
  • Support solutions journalism and preserve access to all readers who work to liberate cities

Join 1015 other sustainers such as:

  • Shara in Hutchinson, KS at $10/Month
  • Kristin in Rockaway Beach, OR at $30/Year
  • Saskia in Frankfort, MI at $60/Year

Already a member? Log in here. U.S. donations are tax-deductible minus the value of thank-you gifts. Questions? Learn more about our membership options.

or pay by credit card:

All members are automatically signed-up to our email newsletter. You can unsubscribe with one-click at any time.

  • Donate $20 or $5/Month

    20th Anniversary Solutions of the Year magazine