Study casts further doubt on the voluntary carbon market

By Anne C. Mulkern | 07/18/2025 06:20 AM EDT

Auditors who decide whether climate projects on the market are actually helpful have a conflict of interest that encourages approval.

A road separates a stark contrast between brown farmland and green rainforest in the Amazon of Brazil.

Carbon markets raise money for projects such as protecting Brazil's Amazon. But a new study raises questions about whether some projects actually help address climate change. Leo Correa/AP

A major global carbon market is facing renewed scrutiny with a new study questioning the credibility of auditors who decide the validity of projects that claim to help fight climate change.

Auditors are a key part of the world’s voluntary carbon market system, which lets major polluters unofficially offset their greenhouse gas emissions by funding projects such as forest protection.

Although independent auditors are supposed to assess whether the projects actually are helpful, a recent study posted on the University of Pennsylvania Carey Law School research site says they aren’t.

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The study says the system for how auditors are paid creates a conflict of interest that encourages them to approve projects.

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