# Which four kinds of leakage must a carbon credit methodology consider under the Integrity Council for the Voluntary Carbon Market (ICVCM) rules, and what happens to them?

Canonical: https://senseible.earth/answers/ccp-leakage-four-sources-and-how-to-deduct

The framework treats these as the approaches that enable a conservative estimate. Where material, a methodology considers upstream or downstream emissions, activity-shifting, market leakage and ecological leakage, minimises it, and estimates and deducts what remains. Leaving a source out is allowed only where that is conservative.

## The four kinds, in the framework's words

- Upstream or downstream emissions: emissions upstream or downstream of the activity that it impacts. Example in the definitions: emissions from producing a fuel or feedstock the activity uses, such as methane from natural gas production.
- Activity-shifting: the activity causes emissions to shift location. Example: farming displaced from land that is afforested.
- Market leakage: the activity changes supply or demand of an emissions-intensive product or service, so emissions rise or fall elsewhere. Example: less timber harvested in one area leads to more harvesting elsewhere.
- Ecological leakage: the activity affects emissions indirectly in hydrologically connected areas. Example: carbon dioxide from wetland soils if water levels are lowered.

## What the framework expects of the methodology

1. Consider all relevant potential leakage sources for the type of activity, and include all material ones in the quantification, except where leaving one out is conservative.
2. Minimise material leakage through requirements in the methodology.
3. Estimate and deduct residual leakage from the reductions or removals, including through specific tools or standardised approaches.
4. Make the estimate robust and conservative in light of the uncertainties.

## A note on labels

A footnote says it does not matter whether an increase in emissions is formally called leakage, as long as all material effects of an activity on emissions are accounted for.

## Our reading for a factory fuel switch

If a coal boiler moves to biomass, the diesel burnt trucking the biomass is an upstream emission the project may have to count. Check your methodology for the exact rule.

## Biomass trucking deducted from a fuel-switch saving

- Reduction against the coal baseline: 1,000 tonnes of carbon dioxide equivalent (CO2e) a year
- Diesel for biomass transport: 40,000 litres x 2.645 kilograms (kg) of carbon dioxide (CO2) per litre = 105,800 kg = 105.8 tonnes
- Net after deducting this one leakage source: 1,000 minus 105.8 = 894.2 tonnes of CO2e

The 1,000 tonnes and 40,000 litres are example figures. Diesel at 2.645 kg CO2 per litre is the factor Senseible uses. It counts carbon dioxide only, so the small methane and nitrous oxide from burning diesel are left out of this example. A real methodology may list other leakage sources too.

## What Senseible does here

Senseible reads fuel invoices and electricity bills into monthly records, which gives a project its own fuel and power history. Credits are issued by the program's registry and checked by an independent verifier, not by Senseible's own check. Diesel invoices for transport give the litres this deduction needs.

- [Displaced farming leakage in afforestation](https://senseible.earth/answers/ccts-afforestation-displaced-farming-leakage)
- [Biomass emissions and leakage tool](https://senseible.earth/answers/ccts-tool-bm-t-010-biomass-emissions-leakage)
- [Coal to biomass boiler and carbon credits](https://senseible.earth/answers/coal-to-biomass-boiler-carbon-credits)
- [Free calculators](https://senseible.earth/calculators)

Sources: [Integrity Council for the Voluntary Carbon Market, Core Carbon Principles Assessment Framework, Section 4, January 2024, version 1.1 (criterion 10.5)](https://icvcm.org/wp-content/uploads/2024/02/CCP-Section-4-V1.1-FINAL-15May24.pdf), [Integrity Council for the Voluntary Carbon Market, Core Carbon Principles Definitions, Section 5, January 2024, version 1.1](https://icvcm.org/wp-content/uploads/2024/02/CCP-Section-5-V1.1-FINAL-15May24.pdf)

Last reviewed 2026-11-05. Based on Assessment Framework version 1.1 (January 2024). The Integrity Council's August 2026 rule architecture says Interpretations and Technical Notices may affect how criteria are assessed, so check icvcm.org for any in effect before you rely on a detail.