GCAM: Global Change Assessment Model

Integrated Assessment Model, in collaboration with the Pacific Northwest National Laboratories (PNNL)


The GCAM model is a global, dynamic-recursive, economic equilibrium model that solves in five-year time steps to the year 2095. The model has been used in both the 4th and 5th IPCC Assessment reports. The model is used by researchers to examine long-term interactions between the energy, agriculture, and climate systems. The main strengths of GCAM are its global scope and the ease with which it can be updated by users, particularly for different climate and technology scenarios. Work in ITS on GCAM began in the spring of 2011. Today, we maintain a close relationship with model developers at the PNNL office in Washington D.C. and regularly participate in GCAM community meetings.


GCAM inputs exogenously-specified population, GDP-per capita, policy parameters, and technological parameters to estimate energy, energy service, agricultural land use, agricultural output, and climate indicators. The mode runs in C++ and inputs XML files. More information is available at the GCAM website (http://www.globalchange.umd.edu/models/gcam/).


  • Global Energy Efficiency. Estimation of global energy efficiency, by primary energy resource, from primary to useful energy. Output:  multiple conference and invited presentations and journal paper (Sonia Yeh, Gouri Shankar Mishra, Geoff Morrison, Jacob Teter, Raul Quiceno, Kenneth Gillingham, and Xavier Riera-Palou (2013) Long-Term Shifts in Life-Cycle Energy Efficiency and Carbon Intensity, Environmental Science & Technology 2013 47 (6), 2494-2501). Database
  • Decomposition Analysis: decomposition of five drivers of energy use and CO2 emissions in achieving climate change goals over 2005-2095. Output: conference presentations at NextSTEPs Symposium and GCAM community meeting. Manuscript currently under peer-review.
  • Transportation Update: updated version of the GCAM model. Output: conference presentation at USAEE, TRB, Transportation Economics, NextSTEPs conference. Manuscript under preparation for peer-review. Model documentation
  • Global Carbon Intensity of Biofuels: Research examines expected reductions in the carbon intensity (grams CO2e/MJ) of the upstream stages of advanced biofuel production due to shifting agricultural productivities and land use patterns. Output: conference presentation at LCA XIII conference, NextSTEPs conference. Manuscript in preparation for peer-reviewed journal.
  • Monte-Carlo Simulation: uncertainty analysis of key input parameters of GCAM using monte carlo analysis.



Dr. Sonia Yeh


Gouri Shankar Mishra, PhD student

Geoff Morrison, postdoctoral researcher

Dr. Rich Plevin, research scientist

Jacob Teter, PhD student

Mohammadsaleh Zakerinia, PhD student