Nitrous oxide ("laughing gas") is a powerful greenhouse gas. As such, it is regulated under the Kyoto Protocol, and New Zealand must account (and if necessary, pay) for its emissions. But according to a piece in the Guardian today, its also a fairly nasty ozone depleter, which has become the "elephant in the room" of man-made, ozone-depleting chemicals. With the decline in CFCs thanks to the Montreal Protocol, it is now the largest ozone-depleting substance we produce, and scientists are calling for it to be brought into the Protocol regime and controlled.
Overseas, most nitrous oxide is produced by industrial processes. Here, it is mostly produced by two things: fertiliser use, and cowpiss. Farmers have reacted strongly to any efforts to make them pay for the damage they are doing to the global climate, and many have retreated into deep denial rather than admit that their actions have consequences. If international pressure to control nitrous oxide grows, I expect them to do the same. Ozone denial, anyone?
