The estimated carbon content of combusted fossil fuels representing the maximum potential emissions to the atmosphere if all carbon in the fuel were to be oxidized during combustion.  [SourceAnnex 2 Methodology and Data for Estimating CO2 Emissions from Fossil Fuel Combustion, Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2010, 2012; U.S. Environmental Protection Agency; p.A-56.]