CSDMS 2021: Changing Landscapes and Seascapes: Modeling for Discovery, Decision Making, and Communication

GCAM and Demeter: A global, integrated human-Earth systems perspective to modeling land projections

Chris Vernon

Pacific Northwest National Laboratory, United States
Pralit Patel Pacific Northwest National Laboratory United States

Researchers and decision makers are increasingly interested in understanding the many ways in which human and Earth systems interact with one another, at scales from local (e.g., a city) to regional to global. For example, how might changes in population, income, or technology development alter crop production, energy demand, or water withdrawals? How do changes in one region's demand for energy affect energy, water, and land in other regions? This session will focus on two models – GCAM and Demeter – that provide capabilities to address these types of questions.

GCAM is an open-source, global, market equilibrium model that represents the linkages between energy, water, land, climate, and economic systems. A strength of GCAM is that it can be used to quickly explore, and quantify the uncertainty in, a large number of alternate future scenarios while accounting for multi-sector, human-Earth system dynamics. One of GCAM’s many outputs is projected land cover/use by subregion. Subregional projections provide context and can be used to understand regional land dynamics; however, Earth System Models (ESMs) generally require gridded representations of land at finer scales. Demeter, a land use and land cover disaggregation model, was created to provide this service. Demeter directly ingests land projections from GCAM and creates gridded products that match the desired resolution and land class requirements of the user.

This clinic will introduce both GCAM and Demeter at a high-level. We will also provide a hands-on walk through for a reference case so attendees can become familiar with configuring and running these two models. Our goal will be for attendees to leave the clinic with an understanding of 1) the value of capturing a global perspective when informing subregional and local analysis, 2) possibilities to conduct scenario exploration experiments that capture multi-sector/scale dynamics, 3) and a hands-on experience with GCAM and Demeter.

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Of interest for:
  • Terrestrial Working Group
  • Human Dimensions Focus Research Group
  • Ecosystem Dynamics Focus Research Group
  • Modeling Platform Interoperability Initiative