Fluorinated gases pharmaceutical industries, as well as in refrigeration when combined with other gases. PFCs were commonly used as fire extinguishants in the past and are still found in older fire protection systems. They are also a by-product of the aluminium smelting process. Sulphur hexafluoride (SF) is used primarily as an insulation gas. It can be found in high-voltage switchgear and is used in the production of magnesium. HFCs were developed in the 1990s to substitute substances such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). As these substances were found to deplete the ozone layer, the Montreal Protocol lays down provisions for them
Canada and the Kyoto Protocol of compliance has been estimated 20 times lower. States for which the emissions are not covered by the Kyoto Protocol (the US and China) have the largest emissions, being responsible for 41% of the Kyoto Protocol. China's emissions increased by over 200% from 1990 to 2009. Canadian Council of Chief Executives VP John Dillon argued (2011-11-22) that a further extension of Kyoto would not be effective as many countries, not just Canada, were not on track to meet their 1997 Kyoto commitments to reduce emissions. He called for a comprehensive, long-term global agreement that includes major emitters like the US,