An emission projection consists of estimates of future trends in emissions of air pollutants, based on a set of assumptions about changes in key parameters. For example, emission projections may require assumptions to be made regarding future levels of activity such as industrial producion, or consumption of fuels or materials, as well as how emission factors may change over time, perhaps in response to technological changes, or the introduction of additional regulation.
In order to ensure consistency between estimates of historic and projected emissions, both should be based on the same structure. Therefore, projections are made using a similar method to that used to calculate historic emissions. Historical emissions are calculated by combining an emission factor (for example, kilograms of a pollutant per million tonnes of fuel consumed) with an activity statistic (for example, million tonnes of fuel consumed).
For example, historic emissions:
E2022 = A2022 * EF2022
where E = emission, A = activity and EF = emission factor, for a given source, all for the year 2022.
For projected emissions:
E2030 = A2030 * EF2030
Where E = emission, A = activity and EF = emission factor, all for the year 2030.
Air Quality projections
Projected emissions for the five National Emission Ceiling Regulations (NECR) pollutants and particulate matter are compiled, as required by Defra, by the NAEI team in Ricardo and submitted to meet international reporting requirements. A summary of the latest forecasts was submitted in December 2011 under the NECD reporting requirements.
Emission projections are also submitted under the NECR every 2 years, with the latest dataset being published under the Air Pollutant Emissions Data page.
The NAEI projection methodology broadly follows the methodology outlined in the EMEP/EEA Emission Inventory Guidebook 2019.
Get data
For air quality pollutants, the latest UK NECR and CLRTAP submissions are available from the Air Pollutant Emissions Data page.
Emissions projections reports can be found on the Reports page.