This article discusses Global Learning and Observations to Benefit the Environment (GLOBE), a worldwide, hands-on science and education program for primary and secondary students. GLOBE brings together students, teachers, scientists, and community members to collaborate on inquiry-based investigations of the environment. Now in its 13th year, more than 40,000 teachers from more than 21,000 schools around the world have been trained in the GLOBE methodology, and students have contributed more than 18 million measurements to the GLOBE database. This currently encompasses four broad investigation areas: (1) atmosphere and climate; (2) hydrology; (3) land cover biology; and (4) soil. Current large-scale earth system science projects focus on seasons and biomes, carbon cycle, watershed dynamics, and local and extreme environments. How the GLOBE program works is described.