Abstract for talk, "Uncertainty and Integrated Assessment" by Mort Webster

This talk will describe the propagation of uncertainties in both economics and climate science through an integrated assessment model of climate change, the MIT Integrated Global Systems Model (IGSM). The IGSM couples a detailed 16-region general equilibrium model of economic trade and energy technology with an earth system model of intermediate complexity (EMIC), consisting of a 2-dimensional atmospheric model, detailed photochemistry, and a 3-D ocean general circulation model. I will show results from propagating uncertainty in key parameters in this model using Monte Carlo techniques. The resulting uncertainty information can then be used in framing a sequential decision analysis of climate policy over time. The consideration of climate policies for the next decade or two are not now or never decisions, but rather decisions that are made with the expectation that we might reduce uncertainties in the future and will revise our policies to reflect new information. I will show the effect of uncertainty and learning on near-term climate policy decisions. Finally, I will share preliminary results from current research to calculate how uncertainty in the climate system will be reduced simply by observing several more decades of global temperature trends. The effect of the reduced uncertainty will be applied in the sequential decision model to explore how it changes today�s decision.