Double counting
Counting the same emission reduction or removal more than once in ways that undermine the intended accounting rules.
Example
This can arise through duplicate issuance, multiple uses or overlapping claims.
The catch
Legitimate overlap in different inventory scopes requires separate explanation.
In more depth
Double counting, explained.
Double counting makes climate progress look larger than it is, because the same tonne of reduction ends up supporting two claims. A landfill operator that sells credits for flaring its gas, then claims the lower emissions against its own climate target, has created two claims on a single cut. The ICVCM lists its absence among the Core Carbon Principles, and registries guard against the simplest forms with unique serial numbers and checks for projects listed twice.
The harder case involves countries. Under the Paris Agreement, a country that authorises a reduction for use outside its own target must make a corresponding adjustment, adding the tonnes back to its national accounts so that only the buyer counts them. Credits issued without that authorisation can still be genuine, yet a company that uses one to claim it has offset its emissions may be claiming a tonne the host country also counts towards its national target.
When a claim depends on credits, the registry should show a retirement in the claimant's name, and the wording should match the credit's authorisation status. Look out for the same reduction reappearing in a supplier's or partner's marketing. A contribution claim avoids the country-level problem, because the funder never counts the tonnes as its own.
In the journal