PCMDI was established in 1989 at the Lawrence Livermore National Laboratory (LLNL), located in the San Francisco Bay area, in California. Our staff includes research scientists, computer scientists, and diverse support personnel. We are primarily funded by the Regional and Global Climate Modeling (RGCM) Program and the Atmospheric System Research (ASR) Program of the Climate and Environmental Sciences Division of the U.S. Department of Energy's Office of Science, Biological and Environmental Research (BER) program.

The PCMDI mission is to develop improved methods and tools for the diagnosis and intercomparison of general circulation models (GCMs) that simulate the global climate. The need for innovative analysis of GCM climate simulations is apparent, as increasingly more complex models are developed, while the disagreements among these simulations and relative to climate observations remain significant and poorly understood. The nature and causes of these disagreements must be accounted for in a systematic fashion in order to confidently use GCMs for simulation of putative global climate change.

PCMDI's mission demands that we work on both scientific projects and infrastructural tasks. Our current scientific projects  focus on supporting model intercomparison, on developing a model parameterization testbed, identification of robust Cloud Feedbacks in observations and models and on devising robust statistical methods for climate-change detection/attribution. Examples of ongoing infrastructural tasks include the development of software for data management, visualization, and computation ; the assembly/organization of observational data sets for model validation; and the consistent documentation of climate model features. Details of all this work are described in numerous publications, as well as on this website.

We now also are applying our collective expertise to support modeling studies initiated by the World Climate Research Programme (WCRP). Notably, we are currently providing leadership in managing the Coupled Model Intercomparison Project, Phase 5 (CMIP5). Among PCMDI's role in CMIP5 is responsibility for leading the Earth System Grid Federation (ESGF) which stores and distributes terrascale data sets from multiple coupled ocean-atmosphere global climate model simulations. Extensive analysis of these simulations by members of the international climate community will provide an important scientific basis for the IPCC's Fifth Assessment Report on Climate Change, which is scheduled for publication in 2013.