2 Sep 2009. Laughing gas set to deplete the ozone layer. NewScientist.
28 August 2009. Lisa Grossman. Laughing gas is biggest threat to ozone layer. NewScientist.
21 July 2012. Michael Marshall. Laughing gas may cook the planet. NewScientist.
The ozone layer shields Earth from the sun’s ultraviolet rays, which increase the risk of cancer and threaten crops and aquatic life.
Nitrous oxide is also a heat-trapping greenhouse gas in the league of methane or carbon dioxide, so regulating it would also be good for the climate.
In fact the last ice age may have ended due to a huge release of nitrous oxide 14,500 years ago, when Europe warmed up by about 5 degrees centigrade due to a pulse of nitrous oxide, which is 310 times as warming as carbon dioxide.
The release came from arcitc plants such as peatlands, and could happen again as Arctic ice shrinks.
“If we have climate change proceeding very quickly, the huge amounts of nitrogen stored in our ecosystem may be released as nitrous oxide,” says Klaus Butterbach-Bahl of the Karlsruhe Institute of Technology in Germany.
Nitrous oxide (N2O) emissions, like chlorofluorocarbons (CFCs), deplete ozone but aren’t regulated. Human activity now accounts for nearly 40 per cent of N2O emissions (Science, DOI: 10.1126/science.1176985).
N2O could become 50 per cent more destructive as stratospheric CFCs return to pre-industrial levels. That’s because nitrogen and chlorine compounds counteract each other’s effects on ozone: the more chlorine there is, the less destructive nitrogen is, and vice versa. “N2O is the most important ozone-depleting gas that’s being emitted,” says Ravishankara.