In a brief filed with the state Supreme Court earlier this month, Attorney General Jerry Brown sided with local air regulators fighting a California Public Utilities Commission ruling they say will increase air pollution when liquefied natural gas arrives in California. \u201cUndisputed evidence,\u201d Brown told the High Court, shows that hotter burning LNG \u201cproduces greater emissions of nitrogen oxide, a pollutant that helps cause photochemical smog.\u201d If hot burning imported gas is used in the greater Los Angeles area, Brown said, it will make it more difficult for the South Coast Air Quality Management District to clean up air pollution in the smoggy area. Accordingly, the attorney general asked the justices to require the CPUC to fully review its ruling under the California Environmental Quality Act. \u201cAQMD welcomes the California Attorney General\u2019s intervention in the \u2018hot gas\u2019 lawsuit,\u201d said Sam Atwood, SCAQMD spokesperson. However, a representative of Southern California Gas and San Diego Gas & Electric predicted that the CPUC will prevail in the litigation. \u201cThis is not just an LNG issue\u201d said Denise King, spokesperson for the Sempra utilities. \u201cThis impacts all natural gas supplies.\u201d At issue in the case is a 2006 CPUC ruling that allows LNG sent into the state\u2019s natural gas pipeline system to contain higher levels of ethane, propane, and butane than traditional pipeline gas. SCAQMD challenged the commission ruling on grounds that because those constituents burn hotter, unless removed or treated before LNG is sent into the pipeline system, they would increase nitrogen oxide emissions, which form ozone and fine particulates in the air. Some end users, such as power plant owners, also have voiced fear that a difference in gas quality may affect their turbines. However, King said the gas industry has carefully studied how changing gas compositions affect equipment and air pollution as the areas where gas is produced shift, both domestically and internationally. Based on the studies, she said, the industry is confident that its procedures and the CPUC standards will not cause damage or increase air pollution. She added that assuring better supplies of natural gas should lower costs for consumers and provide more opportunities to replace dirtier fuels, like diesel and gasoline used in vehicles, with cleaner burning natural gas.