California Environmental Quality Act Office of Planning and Research to develop and recommend new guidelines to analyze greenhouse gas impacts under CEQA. California’s Natural Resources Agency adopted new guidelines on December 31, 2009, requiring lead agencies to analyze greenhouse gas emissions under section 15064.4 during their CEQA review through California. The major category of greenhouse gas emissions resulting from human activities is carbon dioxide. Several other primary gases also include methane, nitrous oxide, sulfur hexafluoride, perfluorocarbons, and hydrofluorocarbons. Greenhouse gas sources resulting from project construction activities are typically generated from transportation of materials to the project site and petrol based equipment used during construction
Sulfur hexafluoride the gas's large molar mass. Unlike helium, which has a molar mass of about 4 grams/mol and gives the voice a childish and a "chipmunk like" quality, has a molar mass of about 146 g/mol, and the speed of sound through the gas is about 134 m/s at room temperature, giving the voice a "demonic" quality when is inhaled. For comparison, the molar mass of air, which is about 80% nitrogen and 20% oxygen, is approximately 30 g/mol which leads to a speed of sound of 343 m/s. Sulfur hexafluoride has an anesthetic potency slightly lower than nitrous oxide. Sulfur