Inventories, Forecasts, and Data
An emissions inventory identifies and quantifies the sources and sinks (e.g., forests) of greenhouse gases (GHG). The inventory is usually comprised of these factors: the chemical or physical identity of the pollutants included, the geographic area covered, the time period over which emissions are estimated, and the types of activities that cause the emissions. The main GHGs reported in inventories are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases.
GHG emissions inventories are used by policy makers to understand sources of emissions, to develop strategies to reduce GHGs, and to track progress. Every year, inventories are recalculated and revised, as improvements are made in the analysis methods.
Forecasts of emissions, or estimates of future emissions, assist with the development of policies and actions that can be taken to establish reduction goals and reduce GHG emissions over the long term.