NASA images, showing comparisons between 2005 and 2011, have shown a clear reduction in harmful gas emissions – in particular nitrous oxide (N2O).
Images taken by NASA’s Aura Satellite highlighted huge quantities of N2O, via the ozone monitoring instrument (OMI), in 2005 above most major US cities. N20 is caused by a variety of different factors, but large increases are predominantly down to human activity.
Car emissions, coal power plant waste and water management centres are primary polluters. The poisonous gas can cause negative effects on the respiratory systems in living creatures – especially those with health conditions like Asthma.
Atlanta, Los Angeles and Chicago have shown the most significant drops in emissions, with N20 levels dropping by 40%.
New York City has seen levels drop by 30%, while Houston, Denver and Philadelphia fell by 20%.
The US Environmental Protection Agency (EPA) has encouraged the results, adding that nitrous oxide has fallen 60% nationally between 1980 and 2012, with other pollutants like carbon monoxide and sulphur dioxide also falling dramatically.
This is regardless of an increase in population as well as cars and energy use. The shift, argues NASA, is down to regulations on emissions, improvements in technology and economic changes.
Recent environmental pledges by the Obama administration encourage further reductions in the emission of harmful gasses – largely backed by the Supreme Court.
Photo source: Nevalenx via Flickr