Using satellite data, scientists have produced a first-of-its kind map that details the height of the world's forests. Although there are other local- and regional-scale forest canopy maps, the new map is the first that spans the entire globe based on one uniform method. The map, based on data collected by NASA's ICESat, Terra, and Aqua satellites, should help scientists build an inventory of how much carbon the world's forests store and how fast that carbon cycles through ecosystems and back into the atmosphere.