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Definition

GHG Protocol Project Protocol

The GHG Protocol Project Protocol sets rules for quantifying a mitigation project's greenhouse gas reductions against a justified forward-looking baseline that delivers the same product or service.

What is the GHG Protocol Project Protocol?

The GHG Protocol Project Protocol is the standard for estimating and reporting one climate project's effect against what would happen without it. Its 2005 edition remains in force during the ISO-GHG Protocol update. Use the Corporate Standard for your company's Scope 1, 2 and 3 inventory.

Why does the GHG Protocol Project Protocol matter to you?

A funder, customer or verifier may ask how you proved a reduction. Chapter 11 requires the project description, boundary, baseline, estimate, monitoring plan and periodic results. These records make the subtraction checkable.

How does the GHG Protocol Project Protocol work?

Chapter 5 puts the intended change and significant side effects, meaning emission changes large enough to affect the result, inside the assessment boundary. Chapter 7 identifies alternatives that could deliver the same service in the same place and period. Chapter 8 selects a project-specific baseline by comparing the practical barriers to those alternatives. Chapter 9 can instead set a performance-standard baseline from emission rates for comparable activities. Chapter 10 requires monitored project data, checks on baseline assumptions and documented calculations.

What mistakes should you avoid?

  • Using last year's emissions as the baseline without testing the likely no-project alternative.
  • Comparing options that provide different output, quality or operating time.
  • Ignoring an emission change outside the project site before testing whether it is significant.
  • Subtracting the result from your company inventory instead of reporting it separately.

Is a project baseline the same as a corporate base year?

No. A corporate base year is an actual past reporting period. A project baseline is a supported estimate of future emissions without the intervention. The two numbers answer different questions.

What should you give a reviewer?

Give the reviewer your Chapter 11 report, the alternatives you considered, why you chose the baseline, the assessment boundary and every significance test. Include the activity records, factor versions, formulas, monitoring schedule, quality checks, exclusions and uncertainty.

Keep the source record for every input used in both the no-project baseline and the monitored project calculation.

Example

Hypothetical Netherlands renewable-energy EPC example: Suppose a renewable-energy EPC contractor insulates the gas-heated cable-assembly workshop at its Dutch depot. For calendar year 2026, both cases hold the workshop at 18°C for 2,000 occupied hours and use the same weather-adjustment method. The contractor considers continued operation of the existing uninsulated workshop and a scheduled heater replacement as baseline candidates. Its documented barrier assessment selects continued operation because the existing heater is serviceable, no replacement is budgeted and no applicable rule requires the insulation. The resulting no-project baseline estimate is 500,000 kWh gross calorific value; the monitored project case is 380,000 kWh on the same basis.

Keslio's published dataset contains a 2026 UK DESNZ and DEFRA natural-gas factor of 0.18231 kg CO2e per kWh gross calorific value. The contractor labels this UK value as a temporary proxy because the dataset has no Netherlands gas factor and replaces it if the reviewing programme specifies a Dutch source. Baseline emissions are 500,000 x 0.18231 = 91,155 kg CO2e. Project gas emissions are 380,000 x 0.18231 = 69,277.8 kg CO2e.

The assessment boundary covers the 2026 gas combustion change and the insulation's production and installation. Suppose the supplier declaration and installation records put that side effect at 150 kg CO2e. Project emissions are therefore 69,277.8 + 150 = 69,427.8 kg CO2e. The estimated reduction is 91,155 - 69,427.8 = 21,727.2 kg CO2e, or 21.7272 metric tonnes CO2e. The monitoring file retains the project meter reading, the source data and method behind the baseline estimate, the factor version, the proxy limitation, the supplier declaration and the calculation.

Where it comes up

Assessment boundary for intended and significant side effectsGHG Protocol Project Protocol, Chapter 5, sections 5.1-5.5 (checked 2026-08-20)Official sourceSame-service baseline candidates within a stated geography and periodGHG Protocol Project Protocol, Chapter 7, sections 7.1-7.6 (checked 2026-08-20)Official sourceMonitoring project effects, baseline parameters and data quality controlsGHG Protocol Project Protocol, Chapter 10, section 10.1 (checked 2026-08-20)Official sourceMinimum project report and periodic reduction resultsGHG Protocol Project Protocol, Chapter 11, sections 11.1-11.6 (checked 2026-08-20)Official source

Related terms

GHG Protocol

The GHG Protocol is a suite of standards for deciding which greenhouse gas emissions belong in a company inventory, classifying them as Scope 1, 2 or 3, calculating them, and reporting the methods and boundaries used.

GHG Protocol Corporate Standard

The GHG Protocol Corporate Standard defines the minimum accounting and public-reporting requirements for a company-wide greenhouse gas inventory, including boundaries, Scope 1 and Scope 2 totals, methods, and exclusions.

Avoided emissions

Avoided emissions are estimated greenhouse gas emissions prevented when a solution replaces a credible higher-emitting reference scenario, and they are reported separately from a company’s Scope 1, 2 and 3 inventory.

Emission factor

An emission factor converts a measured activity, such as kilowatt-hours of electricity or litres of fuel, into greenhouse gas emissions by stating the emissions released per unit of that activity.

Sources

  • GHG Protocol

    Assessment boundary, baseline procedures, monitoring, quantification and reporting requirements

    2026-08-20

  • UK Department for Energy Security and Net Zero

    The 2026 natural-gas factor used as a disclosed UK proxy in the worked example

    2026-08-20

  • GHG Protocol

    Current status, intended users and separation from corporate inventory accounting

    2026-08-20

Last verified 2026-08-20

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GHG Protocol Project Protocol Definition | Keslio