Tree

The Global Tree C-Sink Standard is the first tree-based carbon certification that certifies annual carbon uptake. It pioneers with including agroforestry systems and urban trees alongside afforestation and reforestation. Every certified tree is individually geolocated, digitally monitored, and registered in the Global C-Sink Registry.

The Global Tree C-Sink Standard was first published in 2024 and provides a certification framework for carbon sinks generated by living tree biomass — through afforestation, reforestation, natural regeneration, agroforestry, and urban forestry. By including agroforestry systems and urban trees, the standard recognises that trees embedded in agricultural landscapes and cities deliver carbon removal alongside food production, biodiversity, and climate adaptation — and that these sinks deserve the same certification rigour as large-scale reforestation.

The standard is built on digital monitoring, reporting, and verification (dMRV). Accredited dMRV technologies track each certified tree individually, linking every registered CO₂ unit to a specific geolocation. Carbon accounting uses tree species- and region-specific growth models, validated and updated annually through remote sensing and field verification by independent validation and verification bodies (VVBs).

Three biodiversity levels structure the ecological requirements. At the base level, projects must use native or naturalised species and avoid monocultures. Higher levels impose progressively stricter conditions on species diversity, habitat connectivity, and the exclusion of chemical inputs. The biodiversity ranking does not apply to urban tree projects, which follow their own management criteria adapted to the built environment.

Sustainable management is enforced throughout: no clear-cutting is permitted, a minimum of 40% of the carbon stock must be retained at all times, harvested carbon must be documented, and replanting is immediate. Agroforestry projects must include cover crops. Burning of removed biomass is not permitted. The standard accounts for all project emissions and requires that they are compensated within the certified carbon balance.

To address the upfront investment barrier that limits tree-based carbon projects, the standard allows pre-financing based on certified expected growth curves. A project-specific risk assessment, performed by the VVB at initial certification and updated annually, determines the risk margin built into the certified C-sink curve — replacing blanket security discounts with evidence-based, transparent risk scoring.

The standard and its certification are operated by Carbon Standards International. The Ithaka Institute develops and curates the standard.

Link to Global Tree C-Sink Standard (PDF)

Link to Carbon Standards International for further information