The Horizon Europe project CLIMB-FOREST (https://www.climbforest.eu/) seeks robust solutions for forests and forest management in the face of global change. Within the Work Package 2 "Data assessment of processes and their impacts on biodiversity and climate effects of forests", we use carbon flux data from long-term Eddy Covariance monitoring sites to investigate whether additional atmospheric CO2 leads to a weaker growth response for forests, i.e. we are testing the carbon sink saturation hypothesis with site-level data. This document is the Deliverable D2.2 from Task 1 of WP2 of CLIMB-FOREST.