Livestock's Long Shadow "that livestock are responsible for 18 percent of greenhouse gas emissions" GHG emissions arise from feed production (e.g. chemical fertilizer production, deforestation for pasture and feed crops, cultivation of feed crops, feed transport and soil organic matter losses in pastures and feed crops), animal production (e.g. enteric fermentation and methane and nitrous oxide emissions from manure) and as a result of the transportation of animal products. Following this approach the report estimates that livestock contributes to about 9% of total anthropogenic carbon dioxide emissions, but 37% of methane and 65% of nitrous oxide emissions. Along the animal food chain, main
Sulfur hexafluoride with satisfactory accuracy at very low concentrations, and the Earth's atmosphere has a negligible concentration of . Sulfur hexafluoride was used as a non-toxic test gas in an experiment at St. John's Wood tube station in London, United Kingdom on 25 March 2007. The gas was released throughout the station, and monitored as it drifted around. The purpose of the experiment, which had been announced earlier in March by the Secretary of State for Transport Douglas Alexander, was to investigate how toxic gas might spread throughout London Underground stations and buildings during a terrorist attack. Sulfur hexafluoride is also routinely