Federal agencies are required to create inventories of greenhouse gas emissions by Jan. 31, 2011, under Executive Order 13514. The inventory must include emissions of carbon dioxide, methane, nitrous oxide, hydroflourocarbons, perfluorocarbon gases and sulfur hexafluoride.
The guidance clarifies many questions officials have had, such as which agencies are responsible for reporting emissions at shared or leased facilities (the ones that pay the utility bills) and stipulates that agencies also must report emissions associated with government-owned/contractor operated facilities, known as GOCOs.
It also describes buildings that could be excluded from the inventory, such as privately owned structures located on federal land or military installations.
Agencies must report all direct GHG emissions from sources owned or controlled by the agency within what is known as Scope 1, which includes emissions resulting from power generation, vehicle fleets, manufacturing processes and fugitive emissions, such as leaks from landfills or wastewater treatment plants on federal property.
In addition, agencies must account for Scope 2 emissions -- those that occur elsewhere as a result of agency activities, such as emissions at power plants supplying electricity to a federal facility.
The guidance also includes a phased approach for reporting indirect emissions known as Scope 3, such as those occurring as a result of employee travel or commuting, for example. Because reliable data are more difficult to develop in Scope 3 emissions, the guidance notes a substantial portion of these emissions won't be captured in the initial inventories. (Government Executive, 10/6/2010)