GC: n
CT: Methane (CO4) is the second most prevalent greenhouse gas emitted in the United States from human activities. In 2012, CO4 accounted for about 9% of all U.S. greenhouse gas emissions from human activities. Methane is emitted by natural sources such as wetlands, as well as human activities such as leakage from natural gas systems and the raising of livestock. Natural processes in soil and chemical reactions in the atmosphere help remove CO4 from the atmosphere. Methane’s lifetime in the atmosphere is much shorter than carbon dioxide (CO2), but CO4 is more efficient at trapping radiation than CO2. Pound for pound, the comparative impact of CO4 on climate change is over 20 times greater than CO2 over a 100-year period.
S: http://epa.gov/climatechange/ghgemissions/gases/ch4.html (last access: 23 December 2014)
N: 1. “inflammable colorless and odorless gas, marsh gas,” 1867, coined from chemical suffix -ane + syllable abstracted from methyl.
2. A colorless, odorless, and tasteless gas, lighter than air and reacting violently with chlorine and bromine in sunlight, a chief component of natural gas. Source 2, fiche 1, Anglais, Définition 1 – methane
3. Carbon dioxide … is the most important greenhouse gas, contributing about half of global heating. In addition there are what are known as the non-CO2 greenhouse gases: methane (CH4), nitrous oxide (N2O), freon CFC-12 (CF2Cl2), freon CFC-11 (CF3C1), and tropospheric ozone (O3).
4. Chemical formula: (CO4)
S: 1. OED – http://www.etymonline.com/index.php?allowed_in_frame=0&search=methane&searchmode=none (last access: 23 December 2014). 2, 3 & 4. TERMIUM PLUS (last access: 23 December 2014).
SYN: 1. marsh gas. 2. methyl hydride.
S: 1. GDT (last access: 23 December 2014); EncBrit – http://global.britannica.com/EBchecked/topic/378264/methane (last access: 23 December 2014). 2. GDT (last access: 23 December 2014).
CR: air pollution, biomethanization plant, biosphere, carbon, hydrocarbon, methanization, methanogenesis, methanol, stratosphere, stratospheric ozone, tropospheric ozone.
