Earth’s boreal forests circle our planet’s far northern reaches, just south of the Arctic’s treeless tundra. …Because boreal forests and soils face subzero winters and short summers, these forests and the animals that live in them are shifting northward as temperatures rise. …Satellite measurements show that plant growth widely increased along the cold northern margins of the boreal forest in recent decades, but it often decreased along the warm southern margins − potential early indicators that the boreal forest is beginning to migrate northward. …Our combined research shows that boreal forests are, in fact, responding to rising temperatures. But rapid rates of climatic change mean that trees likely can’t move northward at a pace that keeps up with their loss in the south. …Will trees in the far north ever catch up with climate and prevent forest contraction? At this point, scientists simply don’t know.