The report documents the development of national- and state-level emissions estimates of radiatively important trace gases (RITGs). Emissions estimates are presented for the principal anthropogenic sources of carbon dioxide (CO2), methane (CH4), chlorofluorocarbons (CFCs), and ozone precursors. The national annual emissions of CO2, CH4, CFCs, volatile organic compounds (VOCs), nitrogen oxides (NOx), and carbon monoxide (CO), in units of thousands of tons per year, are estimated to be 5,517,223; 33,000; 440; 22,072; 20,541; and 60,938, respectively. Emissions were estimated for these species from readily available data bases and other information. Thus, the emissions estimates presented in the report are not totals of all possible sources and should be interpreted only as estimates of the contributions of some of the major source categories. No estimates of any natural sources of these compounds are presented in the report. The data sources used to estimate the emissions are discussed and referenced.