Definitions: emissions & reporting

Scope 1: Direct emissions

These are emissions that a site directly causes and controls. In this case, the CO2e is actually emitted either at the site or by an asset that the site controls.

Typical examples are:

• Gas burnt for heating or process use on a site directly emits CO2e at the site and is in Scope 1.
• A company car or company truck (owned or on long-term lease) directly emits CO2e at various places but is controlled by the site.
• Leakage of refrigerants, e.g., from chillers, air conditioners or compressed air dryers, is a GHG emission at the site and controlled by the site. Special conversion  factors are used for refrigerant emissions because of their high damaging effect on the atmosphere.

Scope 2: Indirect emissions from imported utilities

These are emissions from purchased electricity or other utilities, e.g. imported heat or steam. In this case, the CO2e is not actually emitted at the site but is emitted some distance from the site by the power station that generated the electricity, heat or steam.

Scope 3: Indirect emissions

These are emissions that a company causes to occur but where it does not control the asset. 

Typical examples are:

• When staff travel by air then the site does not control the asset (the plane) but the journey accepts a portion of the emissions from the flight.
• All transport in vehicles owned by other organisations, e.g., trains, rental cars or commuting, where the site does not control the asset.
• Product transport where the vehicle is not owned by the company, e.g., contract transport companies.
• All emissions related to the full value chain including impact from products sold.

Emission sources and factors

The table below gives a list of common emission sources listed by scope. To create a carbon footprint, ‘activity data’, e.g., distance travelled, litres of fuel used or electricity used must be converted into equivalent CO2e emissions. Conversion factors are available from the UK government. This gives the values to be used to convert activities into CO2e emissions.

• Sites should record and refine CO2e emissions to quantify the carbon footprint.

Reporting Carbon footprints should be reported for a complete year in terms of CO2e.

The scopes for carbon footprinting

The three main divisions of the emissions are used to assess the total emissions from a site or company. The objective is to be consistent in collecting information.

Much of the published guidance is on how to report the available data so that it can be compared with other sites and avoids issues such as ‘double counting’ in the production of a site carbon footprint. Calculating Scope 3 emissions for products is recommended as this can sometimes offer the best opportunities for CO2e reductions.