Leakage, permanence and double counting are three risks that can make a claimed emission reduction smaller than the real one. Leakage is an increase in emissions outside the project boundary caused by the project itself; non-permanence is the release of stored carbon back into the atmosphere; double counting is counting the same tonne twice. Permanence and the absence of double counting are explicitly named among the ICVCM Core Carbon Principles, while accounting for leakage falls under robust quantification.
Leakage
A project reduces emissions within its boundary but can cause them to rise elsewhere. Examples:
- after replacement, the old boiler is not scrapped but sold, and it keeps running at another company;
- production moves to another site where emissions are higher;
- the project increases grid electricity consumption that falls outside the calculation boundary.
Methodologies require either bringing such sources inside the boundary or estimating leakage and deducting it:
Reduction = Baseline emissions − Project emissions − Leakage
Example
A company replaced a gas boiler with a heat pump. Baseline emissions are 306.0 t CO₂e and project emissions 222.3 t CO₂e. The old boiler has been handed over to another organization and will operate there, so the methodology requires leakage to be accounted for. Suppose the calculation puts it at 10.0 t CO₂e a year. The reduction that can be confirmed is then 306.0 − 222.3 − 10.0 = 73.7 t CO₂e. If the boiler is scrapped and this is documented, leakage from this source is zero.
Permanence
Permanence matters for projects that store carbon: forests, soils, CO₂ storage. A fire or logging returns the carbon to the atmosphere, and the units no longer reflect real storage. Programs manage this risk through buffer pools, monitoring after the crediting period ends and replacement obligations.
For energy projects — heat pumps, heat recovery, solar plants — emission reductions are irreversible: gas that was not burned will not be burned later. The permanence risk here is minimal, but equipment durability matters: if an installation stops, the reductions simply stop as well, and monitoring must show this.
Double counting
There are three forms:
- Double issuance — the same tonne is issued in two programs or twice in the same program.
- Double use — the same unit is retired by two buyers.
- Double claiming — a unit is sold to a buyer while the host country counts the same reduction toward its nationally determined contribution.
The safeguard against the first two is registries with unique serial numbers and retirement. The safeguard against the third is corresponding adjustments under Article 6.2 of the Paris Agreement. In Uzbekistan, under PP-110 (2025), the national carbon unit registry is maintained under the Ministry of Economy and Finance; up to 80% of units may be sold abroad, and at least 20% go toward national commitments.
There is also internal double counting: the same reduction in electricity use cannot be claimed both as the result of a solar plant and as the result of an equipment replacement if both projects are at the same facility.
How it works in the platform
- The MRV and carbon market contours are still in development and are marked “Soon” in the platform: there is no carbon unit registry or leakage calculation in it. The leakage justification is prepared by a methodologist under the chosen methodology.
- A single energy balance for the facility helps you check for internal double counting: in Data entry, purchased electricity, heat and fuel for each facility are kept in one place, month by month, with invoices, certificates of completion and photos of meter readings attached.
- Monthly data show whether equipment was running: a month without consumption is marked “No consumption,” and a closed facility year is read-only and keeps its change history. Read more in the article on closing the year and the annual report.
Frequently asked questions
Does leakage need to be accounted for in a small energy project?
If the methodology provides for it, yes — even when the result is zero. The verifier expects to see an analysis and a justification, not a missing section.
Does registration with one program protect against double claiming by the host country?
No. Double claiming between the buyer and the host country is eliminated by corresponding adjustments under Article 6, not by registration with a voluntary program.
What happens if the project equipment breaks down?
No reductions arise for the period of downtime. The monitoring plan must record such periods so that they do not end up in the report.