redOrbit: Emissions of greenhouse gases in the United States rose 1.4 percent in 2007 compared with 2006, according to a report released Wednesday by the U.S. Environmental Protection Agency (EPA). Total emissions of six main greenhouse gases in 2007 were equivalent to 7,150 million metric tons of carbon dioxide, the report said. These gases include methane, carbon dioxide, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. According to the report, U.S. …