Planning and climate change guidance: research report issue 3

1 Terminology

1.1.1. The following definitions have been adopted for consistency. They are primarily based on the internationally recognised carbon management specification, PAS 2080:2023 Carbon Management in Buildings and Infrastructure^[1].

Carbon/Carbon Emissions: Shorthand for all greenhouse gas (GHG) emissions as defined by the Kyoto Protocol, measured in kg or tonnes of carbon dioxide equivalent (CO₂e).

Carbon Budget: The estimated amount of whole life carbon a system can emit. These could be set at a project, sector, local or national level.

Carbon Control: Where project owners have the ability to manage, through direct requirement of project design and operational approach, specific objectives for capital and operational carbon emissions.

Carbon Hotspot: In relation to projects, an element of the project emissions that encompass high levels of carbon e.g. this could appear in a built environment project as the emissions associated with concrete usage in the project.

Carbon Impact: The relative significance of a development in terms of associated carbon emissions.

Carbon Influence: Where the project may affect carbon emissions beyond carbon control, notably through the use of project buildings or infrastructure. For example, a project owner can ‘control’ the carbon associated with a new road (design, construction, maintenance, lighting, etc.) but can only ‘influence’ the carbon emitted by users of the road.

Carbon Mitigation: Efforts to reduce or remove carbon emissions through the implementation of interventions, e.g. by reducing the sources of the emissions or enhancing the storage of the emissions.

Capital Carbon: Carbon associated with the creation, refurbishment, and end of life treatment of a project, e.g. construction materials and processes. The related term ‘embodied carbon’ is usually used at a product or material level, whereas capital carbon will have greater relevance at a project level.

Net Zero Carbon: Where the sum of the carbon emissions resulting from a project and the carbon it removes from the atmosphere equals zero. Noting that carbon savings against a ‘business as usual’ scenario do not necessarily represent carbon removed from the atmosphere.

Net Zero Carbon Building: A building with zero operational carbon emissions or negative operational carbon emissions, achieved through high energy efficiency and the possibly the deployment of renewable generation. For the purpose of this definition, the concept of a net zero carbon building comes from the World Green Building Council.

Net Zero Test: An iterative process of screening and assessment commensurate with influence and impact on carbon emissions.

Operational Carbon: Carbon associated with the operation of a project required to enable it to deliver its service or outcomes, e.g. electricity use or building heating.

tCO₂e: The unit for measuring carbon emissions (tonnes of carbon dioxide equivalent).

Whole Life Carbon (WLC): The sum of carbon from all stages of the project’s life cycle. For the purpose of this definition, this sum includes indirect changes in carbon expected to result from the project (decreases or increases), e.g. a reduction in atmospheric carbon or an increase in vehicular emissions (also referred to as End User carbon).

Whole Life Carbon Assessment (WLCA ): A WLCA is the calculation and reporting of the quantity of carbon impacts expected throughout all life cycle stages of a project, but also includes an assessment of the potential benefits and loads occurring beyond the system boundary. The term is often used interchangeably with Life Cycle Assessment (LCA).