Rapid changes to the climate of the boreal zone have resulted in large-scale 'greening' and range shifts. Feng and others explain these changes at a global scale and with unprecedented spatial and temporal resolution, demonstrating a change in boreal forest demography toward younger stands, an increase in areal extent of boreal forests, and a northward gain that outpaced losses on it southern fringe. These ongoing changes further emphasize the importance of boreal forests to earth system processes and the work in the present manuscript presents a path forward for detailed studies of large-scale land cover changes.