"Government scientists who study the depletion of Earth’s protective ozone layer are pointing to a previously unheralded culprit: nitrous oxide.

Most of the nitrous oxide in the atmosphere emerges naturally, through the action of bacteria in the soil, the researchers say. But the gas is also produced by human activity, through the use of nitrogen-based fertilizers, the application of livestock manure to fields, the burning of biofuels and in other ways.

Though nitrous oxide is not regulated under the Montreal Protocol, the 1987 agreement to limit emissions of ozone-depleting chemicals, the researchers say it is emerging as the leading artificial cause of ozone loss."

Cornelia Dean reports for the New York Times August 27, 2009. [2]