Puro Standard


Download Puro Standard Rules

The carbon markets require the integrity of certification via carbon standards. The Puro Standard is the first carbon removal standard for engineered carbon removal methods in the voluntary carbon market. It consists of high-quality carbon removal methodologies, aligned with the IPCC definition for carbon removal, for products or processes that remove carbon from the atmosphere.

The current removal methodologies are Biochar, Carbonated Materials, Geologically Stored Carbon, Enhanced Rock Weathering, and Terrestrial Storage of Biomass.  

How do we measure carbon removal?

CO2 must be captured from the atmosphere, stabilized, and stored durably. Only then can it be considered removed. The Puro Standard does not credit reduced nor avoided carbon emissions, only net removals.


Puro.earth’s carbon credit is called the CORC, or CO2 Removal Certificate. Each CORC represents one metric ton of CO2 removed from the atmosphere with one of the Puro Standard methodologies. Carbon removal suppliers and projects can enter the carbon markets by getting issued CORCs and selling them to corporations that want to neutralize their carbon emissions or contribute to the growth of the carbon removal industry. This provides a revenue stream to scale up. If you are a potential carbon removal supplier, start here.

Carbon Removal Methodologies

Methodologies specify the carbon removal method’s system boundaries, carbon accounting formulas to establish the net removal amount, environmental safeguards, and the documentation that independent verifiers need to issue carbon credits to a project. The distinguished panel of carbon removal experts that compose Puro.earth's external Advisory Board oversees Puro Standard methodologies and their mandate is to ensure high carbon credit integrity and robust principles for a science-based carbon removal standard.


Third-party independent verifiers are trained by Puro.earth to audit carbon removal project facilities or sites and issue CORCs if the CO2 removal activity complies with methodology requirements. A rigorous verification process confirms that the products or processes are truly carbon net-negative and that environmental safeguards are being followed. CORCs are always issued ex-post after the removal has been produced. Are you interested in becoming a Puro.earth verifier? Please contact us to apply.

General Puro Standard requirements

All carbon removal suppliers need to demonstrate additionality, meaning that the removals are a result of carbon finance, by providing full project financials and counterfactual analysis based on baselines. Even with substantial non-carbon finance support, projects can be additional if an investment is required, risk is present, and/or human capital must be developed. Suppliers must also show that the project is not required by existing laws, regulations, or other binding obligations.  

All suppliers must also demonstrate environmental and social safeguards, and when applicable, the activities shall be developed with informed consent from local communities and other affected stakeholders and have a policy in place to address potential grievances.

Puro Registry

For traceability, transparency and to avoid double counting, CORCs are issued in the Puro Registry where their complete lifecycle is recorded, from issuance to retirement, as emphasized by the likes of Voluntary Carbon Markets Integrity Initiative and ICROA.

To fulfill corporate climate claims, buyers assign an organization as the beneficiary to the CORCs and retire them in the registry, so no other organization can claim the carbon credit. Anyone can go to registry.puro.earth to search for corporations that have made carbon removal claims based on CORCs and find project information and retirement purpose.

Puro Standard Governance

To ensure governance independence, Puro.earth has appointed an independent external Advisory Board. Puro Standard methodologies are co-created with a working group of scientific and industry experts and the external Advisory Board, while the Board of Directors oversees Puro.earth's business operations.


The Puro Standard is an International Carbon Reduction and Offset Alliance (ICROA) Endorsed Standard.

As the first crediting program focused on durable carbon removal with a storage time of 100+ years and up to thousands of years to obtain ICROA endorsement, this is an important milestone for Puro.earth. Many corporations follow the ICROA Code of Best Practice for the purchase of carbon credits and this endorsement helps to increase buyer confidence of CORCs. Our CORCs are 100% fungible to all global buyers of carbon credits for credits validated, verified, and registered under ICROA endorsed voluntary carbon market (VCM) Standards.

If you, like us, think that removals are unavoidable and the only way to restore the balance of CO2 in our atmosphere, join us. Visit our suppliers who are already producing CORCs and visit our Pre-CORC suppliers, projects that need offtake agreements to start or expand operations.

If you are a supplier who wants to be issued CORCs or Pre-CORCs contact us here.
loder image