Technology.am (Aug. 29, 2009) — Scientists say that nitrous oxide has now become the largest ozone-depleting substance emitted through human activities and will continue to do so for many decades. About one-third of global nitrous oxide emissions are from human activities.
“The dramatic reduction in chlorofluorocarbons (CFCs), over the last 20 years is an environmental success story. But manmade nitrous oxide is now the elephant in the room among ozone-depleting substances,” said Ravishankara, director of the NOAA Earth System Research Laboratory (ESRL) chemical sciences division.
Today, nitrous oxide emissions from natural sources and as a byproduct of agricultural fertilization and other industrial processes are more than twice as high as the next leading ozone-depleting gas.
In addition to soil fertilization, nitrous oxide is emitted from livestock manure, sewage treatment, combustion and certain other industrial processes. In nature, bacteria in soil and the oceans break down nitrogen-containing compounds, releasing nitrous oxide.
Nitrous oxide, like CFCs, is stable when emitted at ground level, but breaks down when it reaches the stratosphere to form other gases, called nitrogen oxides, that trigger ozone-destroying reactions.