Earth breathes. In the Northern Hemisphere, ecosystems wake up in the spring, taking in carbon dioxide and exhaling oxygen as they sprout leaves. Meanwhile, in the oceans, microscopic plants drift through the sunlit surface waters and bloom into billions of carbon dioxide-absorbing organisms. While NASA satellites have been monitoring life on Earth since the 1970s, the continuous and global view of life from space began in 1997 with the launch of the Sea-Viewing Wide Field-of-View Sensor, or SeaWiFS satellite. SeaWiFS offered a comprehensive view of life in the ocean, monitoring ocean plants called phytoplankton, a critical food source for marine animals. Combined with data of vegetation on land from multiple sensors, the space-based view of life allows scientists to monitor crop, forest and fisheries health around the globe. But the space agency's scientists have also discovered long-term changes across continents and ocean basins. As NASA begins its third decade of global ocean and land measurements, these discoveries point to important questions about how ecosystems will respond to a changing climate and broad-scale changes in human interaction with the land. Watch the video to learn more.