Photo: Laughing Gas Biggest Threat to Ozone Layer, Study Says



Modern farming practices such as applying fertilizer (above, a farmer fertilizes his fields) may lead to an increase in laughing gas, or nitrous oxide, emissions, scientists said in August 2009.

A rise in the gas could damage the fragile ozone layer, which was on track to recovery by mid-century following a 1987 ban of ozone-destroying chlorofluorocarbons.

Photograph by Unlisted Images/Photolibrary


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