Northern Eurasia carbon sink tracks forest productivity more than rapid warming

A multi-dataset study finds that Northern Eurasian ecosystems absorb about 0.47 plus or minus 0.20 billion tonnes of carbon a year, nearly one-third of the global terrestrial carbon sink, phys.org reported. The work, led with University of Tsukuba involvement and published in Global Biogeochemical Cycles (DOI 10.1029/2025gb008971), combines satellites, data-driven products, atmospheric inversions, dynamic vegetation models, and Earth system models. Despite large differences among sources, the authors report broad agreement on that sink size. The strongest uptake appears in western and southern parts of the region, while sinks weaken toward colder northeastern areas. Those northeastern forests are warming quickly but are generally less productive and more exposed to disturbances such as wildfires. Much of the warming also falls in winter, when frozen soils limit carbon uptake, so rapid temperature rise alone does little to enlarge the regional sink. The study points to forest productivity, sometimes described as site quality or bonitet, as a main control: more productive stands with larger carbon stocks dominate the regional sink, while less productive forests show only limited gains despite fast warming. The authors argue productivity, not warming rate alone, will largely shape how the Northern Eurasian sink evolves under continued climate change.