An emission inventory (or emissions inventory) is an accounting of the amount of pollutants discharged into the atmosphere. An emission inventory usually contains the total emissions for one or more specific greenhouse gases or air pollutants, originating from all source categories in a certain geographical area and within a specified time span, usually a specific year.

An emission inventory is generally characterized by the following aspects:

Emission inventories are compiled for both scientific applications and for use in policy processes.

Emissions and releases to the environment are the starting point of every environmental pollution problem. Information on emissions therefore is an absolute requirement in understanding environmental problems and in monitoring progress towards solving these. Emission inventories provide this type of information.

Emission inventories are developed for a variety of purposes:

Two more or less independent types of emission reporting schemes have been developed:

Examples of the first are the annual emission inventories as reported to the United Nations Framework Convention on Climate Change (UNFCCC) for greenhouse gases and to the UNECE Convention on Long-Range Transboundary Air Pollution (LRTAP) for air pollutants. In the United States, a national emissions inventory is published annually by the United States Environmental Protection Agency. This inventory is called the "National Emissions Inventory", and can be found here: [2]

Examples of the second are the so-called Pollutant Release and Transfer Registers.