GC: n
CT: Nitrous oxide emissions gets produced by both natural and human sources. Important natural sources include soils under natural vegetation and the oceans. Natural sources create 62% of total emissions. Important human sources come from agriculture, fossil fuel combustion and industrial processes. Human-related sources are responsible for 38% of total emissions.
Human activities have added large quantities of reactive nitrogen compounds to the environment and have virtually doubled the mainly natural inputs existing at the beginning of the industrial age. But, a large part of this gets lost and cascades through the Earth’s soils, water ways and atmosphere. This has increased nitrous oxide emissions by about 40-50% over pre-industrial levels.
Before the Industrial Revolution, the atmospheric concentration of nitrous oxide stayed in a safe range of levels because of natural sinks. But for a long time now human activities have been creating emissions much more rapidly than the Earth can remove them. Nitrous oxide levels are now higher today than at any other time during the last 800,000 years.
S: http://whatsyourimpact.org/greenhouse-gases/nitrous-oxide-emissions (last access: 30 December 2016)
N: 1. nitrous (adj): c. 1600, from Latin nitrosus, from nitrum. Originally “of nitre, pertaining to nitre;” more precise use in chemistry (designating a compound in which the nitrogen has a lower valence than the corresponding nitric compound) is from 1780s. Nitrous oxide attested from 1800.
oxide (n): “compound of oxygen with another element,” 1790, from French oxide (1787), coined by G. de Morveau and A. Lavoisier from ox(ygène) + (ac)ide “acid”.
Chemical formula: N2O.
2. A chemical compound which appears under the form of a noncombustible, asphyxiating, colourless, sweet-tasting gas, is soluble in alcohol, ether, and concentrated sulfuric acid, is slightly soluble in water, is derived by thermal decomposition of ammonium nitrate, controlled reduction of nitriles or nitrates, supports combustion, can form explosive mixture with air, narcotic in high concentration, and is used as an anesthetic in dentistry and surgery, a propellant gas in food aerosols, and for leak detection.
3. Nitrous oxide is destroyed by ultraviolet light and has a 150-year residence time in the atmosphere. Concentrations of nitrous oxide are increasing presently at about 0.3%, or 0.7 ppb (part per billion), per year. A 50% increase of the present concentration would raise the mean global temperature between 0.2 and 0.5 C.
4. dinitrogen oxide: form recommended by the IUPAC (International Union of Pure and Applied Chemistry) for the systematic name corresponding to the CAS number 10024-97-2.
5. nitrous oxide: term standardized by Environment Canada and the Translation Bureau for use in the National Inventory Report
S: 1. OED – http://www.etymonline.com/index.php?allowed_in_frame=0&search=nitrous+oxide (last access: 30 December 2016); TERMIUM PLUS – http://goo.gl/PYKFbG (last access: 30 December 2016). 2 to 5. TERMIUM PLUS – http://goo.gl/PYKFbG (last access: 30 December 2016).
SYN: dinitrogen oxide, laughing gas, nitrogen(I) oxide, factitious air.
S: TERMIUM PLUS – http://goo.gl/PYKFbG (last access: 30 December 2016)
CR: air pollution, biosphere, mesopause, mesosphere, ionosphere, manure, nitric acid, nitrogen dioxide, nitrogen oxide, stratosphere, stratospheric ozone, tropospheric ozone.
