Understanding global environmental issues such as global warming, stratospheric ozone depletion, and worldwide air pollution requires the cooperation of scientists across many disciplines. Global change is projected to accelerate through the 21st century and will impact the ecosystems that preserve the habitability of the planet. The Department of Earth System Science (ESS) focuses on how the atmosphere, land, and oceans interact as a system, and how the Earth will change over a human lifetime.

Founded in 1991, the Department of Earth System Science at the University of California, Irvine provides quality education, along with research and teaching opportunities for students interested in the science of the Earth as a system. ESS faculty, researchers, and students conduct research in the areas of atmospheric chemistry, biogeochemical cycles, and climate change. Home to members of the National Academies of Sciences, the department provides opportunities for students to learn from and work with recognized experts in the field. Over the last decade, ESS has earned a reputation as one of the most influential academic departments in the nation devoted to studying the Earth as a system.