Each tree species on Tree-Nation is linked to a certain amount of CO2 offset.
CO2 offset values are always estimations, even when certified. Many factors influence the amount of CO2 a tree can capture: the species, its variety, but also the region and climate where it’s planted, like multiple other factors.
In the forestry sector, usually, carbon sequestration is calculated per hectare. At Tree-Nation we have developed our own method to provide a CO2 value per unique tree so we can link your support to both CO2 and trees.
For each species in a specific project, we take into account the type of climate of the region, tree height, trunk diameter, growth pattern (fast or slow-growing), and a CO2 period for the tree. For this CO2 period, we consider most carbon is captured in the growth period of a tree. This growth period can last 10 to 35 years, depending on the species. For our calculation, we only consider this period and we cap it at 20 years, so no carbon after 20 years is accounted for. It means the trees we plant will offset more than what is accounted for.
When available, we refine our results by contrasting our values with existing certification calculations and with results from scientific literature for similar systems and species and adjust if needed.
Our estimates are meant to be cautious and by design slightly lower than actual figures so that our sponsors can claim the offset values with peace of mind.