The scientific foundation of this calculator

The values shown by this calculator are not rough approximations, but the outcome of an eight-year research effort carried out by a consortium of European universities and research institutions, within the LIFE URBANGREEN project (EU LIFE+ Programme, LIFE17 CCA/IT/000079) and the VERDEVALE project (Interreg V-A Italy–Switzerland). The research measured, in the field — not in a laboratory or on potted young plants — the capacity of established, mature trees and shrubs to absorb CO₂, filter particulate matter and cool the air, across four European cities (Rimini, Kraków, Bolzano, Lugano) chosen for their climatic diversity.

How the data was collected

For CO₂ uptake, around 17,000 leaves on 450 trees of 15 species were measured with an infrared gas analyser (LICOR-6400), distinguishing sun-exposed from shaded leaves; a terrestrial laser scanner (TLS-LiDAR) was also used to reconstruct the woody volume of trunks and branches, to calculate the carbon already stored. For particulate matter, 2,160 leaf samples from 17 species were washed and filtered in the laboratory using a gravimetric technique to measure how much pollution leaves actually retain. For cooling, the transpiration of trees and shrubs (also measured on 308 shrubs of 9 species in Lugano and Bolzano) was quantified using the Penman-Monteith equation. A dedicated study further examined how maintenance practices, such as pruning and irrigation, affect the net balance of ecosystem services.

From field data to a calculation for your tree

This data was translated into species-specific allometric and physiological models, applied through three levels of priority: coefficients measured directly in the field for the species studied; coefficients derived from scientific literature for other species; and, finally, values from the international GlobAllomeTree database when no more specific data is available. The location selected on the map allows the calculator to factor in local weather data (historical and forecast data from DWD and ECMWF ERA5-Land), which are essential for correctly estimating photosynthesis, transpiration and cooling.

Verification and continuous updates

The methodology is published in peer-reviewed international scientific journals and is reviewed by an independent scientific advisory board, which periodically verifies and updates the coefficients as newi research becomes available.

Scientific references

- Fini, A. et al. (2023). CO2-assimilation, sequestration, and storage by urban woody species growing in parks and along streets in two climatic zones. Science of the Total Environment, 903, 166198.

- Vigevani, I. et al. (2022). Particulate pollution capture by seventeen woody species growing in parks and along roads in two European cities. Sustainability, 14(3), 1113.

- Fini, A. et al. (2025). Effects of management on the provisioning of ecosystem services by mature urban trees. Acta Horticulturae, 1429, 43–50.