Campus carbon neutrality 11, 1997 and put into practice on February 16, 2005. The protocol targets industrialized countries because they are the ones producing most of the greenhouse gases. Specific chemicals that it wants to reduce are carbon dioxide, methane, nitrous oxide, Sulfur hexafluoride, hydrofluorocarbons, and perfluorocarbons. Thirty-seven industrialized countries and parts of Europe have signed and are bound by the agreement. The United States is not one of them. The Kyoto Protocol allots a specific amount of greenhouse gas emissions that each country can produce, however, countries can also trade emissions with other countries, resulting in the cap and trade system. If
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