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
Nitrous oxide Thomas Clover invented the "gas-ether inhaler" in 1876, however, it became a common practice at hospitals to initiate all anaesthetic treatments with a mild flow of nitrous oxide, and then gradually increase the anaesthesia with the stronger ether or chloroform. Clover's gas-ether inhaler was designed to supply the patient with nitrous oxide and ether at the same time, with the exact mixture being controlled by the operator of the device. It remained in use by many hospitals until the 1930s. Although hospitals today are using a more advanced anaesthetic machine, these machines still use the same principle launched with Clover's