A Circumpolar Perspective on the Contribution of Trees to the Boreal Forest Carbon Balance Partitioned estimates of the boreal forest carbon (C) sink components are crucial for understanding processes and developing science-driven adaptation and mitigation strategies under climate change. Here, we provide a concise tree-centered overview of the boreal forest C balance and offer a circumpolar perspective on the contribution of trees to boreal forest C dynamics. We combine an ant’s-eye view, based on quantitative in situ observations of C balance, with a bird’s-eye perspective on C dynamics across the circumboreal region using large-scale data sets. We conclude with an outlook addressing the trajectories of the circumboreal C dynamics in response to projected environmental changes. 74 271-294 271-294 Springer Nature