As moderated by climate and atmospheric composition, the global-scale interactions of human systems and terrestrial systems are complex. Energy use, agricultural practices, and demographics are entwined with the desire of people to improve their well-being and to manage economic growth and its effects through well-meaning but sometimes misdirected policies. The goal of this interdisciplinary research project is to evaluate fundamental interactions between human and terrestrial systems through agriculture and land use, both of which are impacted by forces that are global in nature and moderated by climate and atmospheric composition. The approach that will be used to model these interactions entails use of complex but separate models of human activity, the atmosphere and ocean, terrestrial systems, and sector-by-sector models of economic and human effects. The researchers plan to develop the dynamic linkages needed between a complex global model of the economy and a complex model of terrestrial systems to evaluate these costs and potential feedbacks of changes in atmospheric composition and climate. The proposed work is to link the MIT Emissions Prediction and Policy Analysis (EPPA) model, and the Terrestrial Ecosystems Model (TEM) to dynamically simulate changes in crop productivity driven by environmental change and the economic consequences and changes in land use driven by changes in trade in agriculture and the price of agricultural goods. The work will take advantage of existing capabilities of the two models with some additional improvements needed to make the linkages between them. Principally, this involves further disaggregating the agricultural sector of EPPA and linking the economic data to a supplemental data set on physical land use being developed at the Global Trade Analysis Project (GTAP) at Purdue University. The project also will involve the development of a mosaic approach in the TEM to represent the regions and land uses represented in EPPA. These developments will allow simulation studies of the dynamic linkages among terrestrial systems, land use, the economy, international trade, and economic policy as affected by such changes in climate and atmospheric composition as increasing levels of carbon dioxide and tropospheric ozone.
This project will constitute a first attempt to study complex interactions between terrestrial systems and the economy in a fully coupled model at the global scale. Project results will help to inform policies designed to mitigate different environmental and economic problems, showing where policies may complement one another and where they may be in conflict. This project is supported by an award resulting from the FY 2004 special competition in Biocomplexity in the Environment focusing on the Dynamics of Coupled Natural and Human Systems.
