Use of a State-Level Integrated Assessment Model for Policy Analysis: An Uncertainty Analysis of Energy and Water
This presentation discusses some recent uncertainty assessment work being done on climate policy issues at the state level. The work is being done with the Platform for Regional Integrated Modeling and Analysis (PRIMA), a new climate change policy assessment framework developed at Pacific Northwest National Laboratory in Richland and Seattle, Washington and College Park, Maryland. The central computaional engine of PRIMA is the Global Change Assessment Model (GCAM), a dynamic-recursive integrated assessment model of the world economy, climate policy, and climate change that that has been regionalized to provide policy analysis down to the level of U.S. states. The PRIMA framework also includes detailed sectoral models that address issues in the energy-land-water interface geospatially at the sub-national level as the climate change and socioeconomic change occur. This presentation illustrates two uncertainty analyses conducted with GCAM and with water demand and supply components of PRIMA. The energy uncertainty analysis was conducted with GCAM alone and examines the impact of aggressive residential and commercial building equipment standards across the United States in the context of socioeconomic and climate uncertainty. The analysis focuses on the impact on future net energy service costs under aggressive standards in the residential and commercial building sectors from 2005 to 2050. The analysis uses a combination of discrete scenarios and Monte Carlo sampling approaches to address uncertainties. Results for Arizona and Florida are used to illustrate whether aggressive building equipment standards save energy and reduce net energy service costs when compared with current standards. Analysis of the output indicates a robust result under a broad range of future socioeconomic, policy, and climate scenarios. The water uncertainty analysis demonstrates a multi-model approach used to bound the prospects for future water shortages in Florida, given socioeconomic uncertainty and future water supply under a future climate. In this analysis, water demands from GCAM are coupled with a water management model that simulates regulated streamflows and water supply deficits given naturalized streamflows, water demands, and reservoir operating rules. The naturalized streamflows are simulated with a regional earth system model coupled to a river routing model. The climate is obtained from a regional climate projection of the Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathway 8.5 (RCP 8.5) for all of the river basins in the United States. GCAM is used in Monte Carlo mode to estimate the outer bounds of water demand given socioeconomic uncertainty and RCP 8.5 climate. Future water demand is downscaled to a river basin level for Florida in high, low, and middle cases and is compared with available water supply for the same region for RCP 8.5 climate to identify the potential location and severity of water shortages.