Unraveling the carbon sequestration in trees and its potential improvement to mitigate climate change requires knowledge from and interaction between many branches of science and society. Understanding of the carbon sink effect in trees at a molecular level is still relatively superficial compared to many other aspects of this complex problem. The Principal Investigators of TreeBio CoE constitute a long tradition and scientific continuum of the studies on the physiology and genetic regulation of CO2 uptake through stomata, long distance transport and radial growth in trees. In order to approach the tree traits significant for the carbon sink effect and to integrate our research on the role of trees in forest vegetation as key carbon storage, we are consolidating here our approach by expanding our consortium to a multidisciplinary team representing a broad base in tree genetics, physiology and computational modelling of whole tree physiology.