Boreal and temperate forests have experienced substantial climate change over the last several decades.  However, understanding of how changes in climate are affecting these ecosystems is incomplete.  Remote sensing provides an important source of information that can help address this information gap.  We present results from recent studies that use three decades of Landsat imagery to map and characterize climate-driven changes in North American temperate and boreal forests, focusing on three main questions: (1) What is the nature and magnitude of so-called “greening and browning” in Canadian boreal forests? (2) Has the timing of spring time phenology in boreal and temperate forests changed, and what is the sensitivity of springtime phenology to climate variation? And (3) Is the overall distribution of plant functional types in boreal and arctic regions changing, and if so, how?