Eruptions can’t be prevented, so scientists have focused on improving early detection technologies. New work being done by NASA and the Smithsonian Institution builds upon the existing knowledge that changes in tree leaves can signify a volcanic eruption. Magma releases carbon dioxide, sulphur dioxide, and other gases as it ascends. Nearby trees absorb the carbon dioxide and become greener and more lush in response. According to the new research, these changes are detectable from space. The greener foliage can be read by NASA satellites like Landsat 8, as well as airborne instruments from the Airborne Validation Unified Experiment: Land to Ocean (AVUELO). There are roughly 1350 active volcanoes in the world, many of them in remote or hard-to-navigate terrain. Volcanic carbon dioxide is difficult to detect remotely. Scientists often have to travel to volcanoes to take direct measurements, which is a difficult and sometimes hazardous assignment.