Global Change Analysis Model

JGCRI is the home and primary development institution for the Global Change Analysis Model (GCAM), an integrated tool for exploring the dynamics of the coupled human-Earth system and the response of this system to global changes. GCAM is a global model that represents the behavior of, and interactions between five systems: the energy system, water, agriculture and land use, the economy, and the climate. Throughout its lifetime, GCAM has evolved in response to the need to address an expanding set of science and assessment questions.

PNNL is the steward of the GCAM model, whose development dates back to 1981, and is now a freely available community model (see GCAM Community). The team at JGCRI is comprised of economists, engineers, energy experts, forest ecologists, agricultural scientists, hydrologists, and Earth system scientists who develop the model and apply it to a range of science and policy research questions.

For a description of the model, and on-line documentation, see the GCAM On-line Documentation.

Contacts: Pralit Patel ( or Kate Calvin  (

Model Tutorials:

For detailed information see the GCAM Online Documentation, which includes a guide on “How to Get Started Running GCAM”. Copies of GCAM tutorial presentations from the annual GCAM meeting are available on the GCAM Community page. Questions about the model can be posted on the Issues section of the GCAM GitHub site.

Model Availability:

GCAM is available as open source software and is now hosted on GitHub.