Climate modelling and policy strategies. The role of technical change and uncertainty

This paper provides a brief outline of the most recent advances of economic -environmental quantitative modelling. After having described some of the m ost relevant methodological approaches, the paper focuses on the drawbacks of present models and outlines directions for modelling improvements. Two m ethodological issues are emphasised: the treatment of uncertainty and the e ndogenisation of technical progress. The paper describes how recent works, particularly those included in this special issue, tackle these two importa nt problems and which solutions, albeit preliminary, have recently been pro posed. It is also stressed how results achieved with models where uncertain ty and technical change are adequately dealt with largely differ from those obtained from traditional models. (C) 1998 Elsevier Science B.V. All right s reserved.