Endogenous technological change in climate-energy-economic models : an inventory of key uncertainties

This article gives an overview of uncertainties related to endogenous technological change as observed in IAMs of global warming, both for bottom-up and top-down climate-energyeconomic models. A classification is formulated by which uncertainties can be evaluated, and through which one can distinguish between modelling, methodological and parameter uncertainties. We emphasise that the analysis of uncertainties in IAM exercises of global warming is essential for both scientific and policy-related reasons. At present, proper analyses of the sensitivity and robustness characteristics of modelling results are often neglected. Our main conclusion, and recommendation, is that in future IAM analyses of climate change, both for the benefit of scientists and public policy decision makers, the presence of different kinds of major uncertainties should be appropriately recognised, classified, quantified and reported.