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Double counting carbon credits

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What is Double Counting?

Double counting refers to credits of the same vintage from the same project being sold twice. This is despite only one tonne of carbon dioxide, represented by that credit, having been removed from or avoided being released into the atmosphere.

This can happen to offsetters working with intermediaries connected to projects whose sales and credit cancellation processes haven’t been independently verified. More commonly, double counting results from poor accounting of credits issued from a project hosted in country that engages in emissions trading, domestically or internationally. A country could use a credit for its nationally determined contribution under the Paris Agreement, while a company is trying to claim that same credit for its own climate ambitions.

Why does Double Counting Matter?

When a credit is claimed by two parties, the environmental value of the credit is cast into doubt. Double counting gives the impression of more emissions reductions and removals than has actually been achieved. This can mean that atmospheric pollution and warming are not only still taking place, but that we are not aware of the true rate at which it is happening. Offsetters can fail to realise their climate targets, and spend a significant amount of money on doing so.

This issue undermines the effectiveness of the voluntary carbon market in tackling greenhouse gas emissions and anthropogenic climate change.

How is this Prevented?

Official guidelines from certifying bodies which operate in countries that engage in greenhouse gas emissions reductions through mechanisms agreed in the Kyoto Protocol, such as Gold Standard, state that:

  1. The Project Developer may seek evidence to demonstrate to Gold Standard that their issuance is not at any risk.
  2. The Project Developer may cancel a valid/eligible unit as applicable within the host country/international accounting mechanism.

Many certifying bodies and projects have a retirements page with a bookkeeping function. They show how many credits of a certain vintage were issued, sold, and ‘retired’ – or taken out of circulation. This allows for a certain degree of traceability. It prevents companies from making false claims about how much they’ve offset. It also prevents the project from selling the same credits more than once.


This image shows verified carbon units (VCUs) from the Envira Amazonia REDD+ project currently available on our Offset Marketplace. The certifying body, Verra, has made a range of information about all the projects it works with publicly available. It tracks the availability of VCUs at a certain vintage. Information about how many of those were retired in what year, by which buyer are also free to consult. This transparency fosters greater trust in both project developers and those who want to use credits to offset their emissions.

What is Plannet Zero doing to avoid Double Counting?

Plannet Zero aims to buy directly from developers. Working close to the source of the credits reduces the likelihood of accidental and fraudulent double counting. This keeps the cost down for our customers and directs more revenue to projects performing vital environmental services.

If this is something you want to get involved in or learn more about, please get in touch with a member of the Plannet Zero team, or email

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