akar.earthDouble counting: Definition
What is double counting in carbon markets? Double issuance, double use and double claiming explained, and how corresponding adjustments prevent it.
Double counting is when a single tonne of greenhouse gas reduction or removal is counted more than once toward climate goals or claims. It undermines the environmental integrity of carbon markets because the atmosphere only benefits once.
Why it matters
If two parties claim the same tonne, real emissions are higher than reported. Avoiding double counting is one of the ICVCM’s Core Carbon Principles and a central rule of Article 6 of the Paris Agreement. It is also a key risk buyers check in due diligence.
Types
- Double issuance: the same reduction is credited twice, for example by two standards or by overlapping projects.
- Double use: one credit is retired twice or used for two claims, often due to registry errors.
- Double claiming: a company counts the credit toward its target while the host country counts the same reduction toward its NDC.
How it is prevented
- Registries with unique serial numbers and public retirement records.
- Checks for overlapping project boundaries, including nesting in jurisdictional programmes.
- Corresponding adjustments under Article 6, where the host country adds the transferred amount back to its emissions balance.
Indonesia and Southeast Asia angle
Indonesia’s carbon trading rules link domestic and international trading to national authorisation, recording in SRUK and, for international transfers, corresponding adjustments. Forest projects also sit inside the FOLU Net Sink accounting, so overlap with national targets is a live issue. See corresponding adjustments in Indonesia and Article 6.2 ITMOs.
Data systems matter here as much as rules. Registries must talk to each other, project boundaries must be published as maps, and retirements must name the beneficiary and purpose. Buyers should ask sellers how each of these is handled before signing, because the reputational risk of double claims falls on the company making the claim.
Common mistakes
- Registering the same area under two programmes.
- Assuming voluntary credits never need adjustments.
- Retiring credits on behalf of one client but reporting them to two.
See the Article 6 hub.
Frequently asked questions
What are the three types of double counting?
Double issuance (two credits for the same tonne), double use (one credit retired twice or used for two claims) and double claiming (both a company and a country count the same reduction toward their targets).
Does double claiming matter for voluntary buyers?
It depends on the claim. Contribution claims may not need a corresponding adjustment; offsetting or compliance use usually does. Standards and buyers differ on this point.