Climate and Earth System Modeling is a research area for the Climate and Environmental Sciences Division in the Office of Biological and Environmental Research within the Department of Energy's Office of Science. CESM consists of three research programs: Earth System Modeling, Regional & Global Climate Modeling, and Integrated Assessment Research. These programs focus on the development, evaluation, and use of regional and global models, development of Earth system models, and development of integrated assessment models to determine the impacts and possible mitigation of climate change.