Laughing gas from cow pee – a solution

Following Improbable’s recent note regarding Greenhouse gasses in a greenhouse, we ask : ‘How many patches of cow urine would a dentist need in order to perform a tooth extraction?’ The question is not as laughable as it might seem because Nitrous Oxide (or N₂O, or ‘laughing gas’) is produced in prodigious quantities worldwide by the natural degradation of animal wastes on agricultural land.
The US Environmental Protection Agency puts the figure for manure management emissions in the US alone at around 17 million metric tons per year (in CO₂ equivalents). Unfortunately, aside from its anaesthetic (and other*) uses, N₂O is also a powerful ‘greenhouse gas’ – and thus various strategies are proposed to limit its emissions. See for example: Biochar Incorporation into Pasture Soil Suppresses in situ Nitrous Oxide Emissions from Ruminant Urine Patches (published in the Journal of Environmental Quality. 2011 Mar-Apr;40(2):468-76.)

* Some other uses for N₂O are described:
• here (page 8 in the .pdf)
• here
• here and
• here