Global warming has profoundly impacted forest ecosystems, particularly in boreal and alpine regions. Rising temperatures and extended growing seasons have accelerated tree growth by enhancing photosynthesis and increasing nutrient uptake. However, this rapid growth often comes at a cost: compromised structural integrity, heightened vulnerability to environmental stressors, and ultimately, reduced lifespan. By synthesizing recent tree-ring analyses and physiological studies, this talk will explore the ecophysiological mechanisms behind global warming’s dual effects on tree growth and longevity in cold regions. Moreover, the broader implications for carbon sequestration, forest stability, biodiversity, and the future dynamics of cold-region forests will be discussed. By highlighting the intricate relationship between accelerated growth and increased mortality, this talk aims to deepen our understanding of the challenges these forests face in a warming world.