Tree-Nation's CO2 offset methodology

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.