Making projections - Greenhouse Gases

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.

GHG projections

DESNZ annually produces energy and GHG emissions projections, which are used to monitor progress towards national and international targets. The projections take into account the impact of UK policies.

Get data

For GHGs, the latest projections can be found on the DESNZ website with more detail about methodology and assumptions.

Emissions projections reports can be found on the Reports page.


Published: 13 March, 2024

Last updated: 23 July, 2024