Compliance
GHG Protocol
The greenhouse gas accounting standard defining Scope 1, 2 and 3 emissions, used as the basis for Carbon Reduction Plans.
Definition
The Greenhouse Gas Protocol is the international accounting standard for measuring and reporting greenhouse gas emissions. It defines the scope structure that UK public procurement relies on: Scope 1 for direct emissions from sources an organisation owns or controls, Scope 2 for indirect emissions from purchased energy, and Scope 3 for all other indirect emissions across the value chain. A Carbon Reduction Plan prepared under PPN Net Zero (PPN 06) must be calculated on this basis.
How it works in practice
Scope 1 covers fuel burned in owned buildings and vehicles, and any process emissions. Scope 2 covers purchased electricity, heat and steam, reported either by the location based method, using grid average factors, or the market based method, using the emissions factors of the specific tariff purchased. Scope 3 is the largest and most difficult category for most suppliers, covering fifteen defined categories including purchased goods and services, business travel, employee commuting, waste, and use of sold products.
For UK public procurement the practical requirement is narrower than the full standard. PPN 06 requires suppliers bidding for central government contracts above five million pounds a year to publish a Carbon Reduction Plan covering Scope 1, Scope 2, and a defined subset of Scope 3: business travel, employee commuting, upstream transportation and distribution, waste generated in operations, and downstream transportation and distribution. That subset exists because it is measurable by most organisations without a full value chain assessment.
The plan must be published on the supplier's website, board approved, and updated at least annually. It must state a commitment to net zero by 2050 with interim targets, and report emissions using a stated base year for comparison. Buyers check that the published plan exists, is current, and uses a recognised methodology. A plan that omits the required Scope 3 subset, or that cannot show its emissions factors and base year, is the most common reason for a compliance challenge at selection stage.
Common questions
Which scopes must a Carbon Reduction Plan cover?
Scope 1 and Scope 2 in full, plus five specified Scope 3 categories: business travel, employee commuting, upstream transportation and distribution, waste generated in operations, and downstream transportation and distribution. Reporting wider Scope 3 categories is permitted and increasingly expected, but not required by PPN 06.
Do we need external verification?
PPN 06 does not require third party verification of the figures. The plan must be approved by the board or an equivalent governing body and published. Some buyers ask for verification or for evidence of the calculation method in clarifications, particularly on large or environmentally sensitive contracts.
How does this relate to ISO 14001?
They serve different purposes. ISO 14001 certifies an environmental management system, meaning the processes an organisation uses to manage environmental impact. The GHG Protocol is a measurement standard for emissions figures. Holding ISO 14001 does not satisfy the Carbon Reduction Plan requirement, and buyers often ask for both.
What base year should we use?
The base year is the reference point against which reductions are measured. It should be a year with complete and reliable data, and it must be stated in the plan. Once chosen it should be kept consistent between annual updates, with recalculation only where there is a structural change such as an acquisition or a significant change in methodology.
