Elizabeth A. Hadly is a global change scientist who has spent more than 30 years studying environmental change in natural landscapes all over the world. Her research has taken her from iconic Yellowstone National Park in the United States, to the top of Mount Kilimanjaro, the Himalayas, the jungles of Rwanda, the Patagonian steppe, and the rain forests of Costa Rica in her ongoing efforts to understand how people are changing the planet.