Tree-Nation's CO2 offset methodology

We calculate our tree species' average volume and carbon dioxide content so that you can offset with peace of mind

Tree-Nations CO2 offset methodology

Tree-Nation is dedicated to making global reforestation accessible by implementing our unique carbon dioxide (CO2) offset methodology, which allows us to offer affordable tree prices and diverse planting options. Our methodology differs from others, such as that of the Verified Carbon Standard (VCS), Climate, Community & Biodiversity (CCB), or Plan Vivo as outlined below:

Traditional certifications Tree-Nation methodology

Offsets calculated per hectare

Offsets calculated per tree

Offsets calculated year-on-year

Offsets calculated over tree lifetime & year-on year

Data measured on site

Multi-source data measures & calculations

Limited species selection

Unlimited species selection

Limited planting methods

Unlimited planting methods

Large projects, only

All project sizes

Our CO2 offset calculations are continuously updated to incorporate additional parameters and increasingly accurate data, collected from our projects during regular site visits. The Tree-Nation methodology, now in its fifth version*, is conducted in three steps:

Calculating tree volume
For each tree species, we use a large set of data including height, trunk diameter, branch/root volume, dry mass, wood density, growth pattern (slow to fast), growth region climate, and average lifespan to estimate a reasonable species dimension average.

The carbon equation
Dry wood is composed of about 50% carbon, 6% hydrogen, 44% oxygen, and trace amounts of inorganics. Once we have a tree species' average dimensions, we determine its average mass, and then derive the amount of carbon that the tree species typically holds.

From carbon to CO2
We utilize a conversion ratio of 3.667, representing the mass of carbon to that of CO2, to translate the average carbon content of a tree of a specific species into its corresponding CO2 value. We cap all species' measurements at ten years old, ensuring that they take place during peak absorption periods (between 10 and 35 years, on average) for swift impact in combatting climate change.

We take a conservative approach in our estimations. Although trees will continue to absorb CO2 beyond our measurement period, the offset figures we provide are guaranteed. This means you can confidently claim the impact listed on your Tree-Nation certificates.

Review our latest methodology versions below, and learn more in our version 5 release note.




V 4.0

Q1 2023

  • Lifetime CO2 per tree capped at 500 Kg per tree, instead of 800 Kg
    Tracking trees’ CO2 levels until they reach overall weight of 500 Kg

V 5.0*

Q1 2024

  • Lifetime CO2 ex-ante cap changed from 20 to 10 years
    Tracking trees’ CO2 levels until they reach 10 years of age

  • Introduction of tree density
    Begun tracking tree density as part of trees’ dimensions

  • Improvement of radius estimation
    Reduced the average radius estimates for all species

  • Introduction of 50 Kg intervals to standardize our values
    Assigned benchmarks to regulate weight records

  • More accurate estimation of tree survival rate per project
    Using historic project visit data to predict future tree survival

  • Increased model prudence ratio 
    Counting 70% of total calculated CO2

*Our newest methodology versions update species' CO2 absorption rates only at the time of
implementation, not retroactively