ClimateBiz: The debate over the best way to reduce greenhouse gas emissions heated up last week with the introduction of a House bill proposing a carbon tax, rather than the cap-and-trade approach. Representative John Larson (D-Conn.) introduced America’s Energy Security Trust Fund Act of 2009, which would tax carbon dioxide emissions at $15 per ton at the source, including refineries, coal mines and shipping terminals for imported fuel, and increase by $10 per year or higher, depending on how …