Necessities and problems of coupling climate and socioeconomic models for integrated assessments studies from an economist's point of view

This presentation has two parts. The first part is more theoretical. We will examine the definition of Integrated Assessment Models of Climate Change and identify their main aims. We will also have look at the differences between climate and socioeconomic models. The second part will be applied. We present the Dynamics of Inertia and Adaptability Model (DIAM). That model will be used to study some of the fundamentals economic parameters of IAMs: the discount rate, the technical progress rate, the flexibility of energy systems, uncertainty and the final concentration target. We won\'t try to be exhaustive, see Weyant1 leading author of the corresponding IPCC chapter for that. Our goal is simply to convince the reader that these non realistic models can profitably be used to analyse real issues.Dans la première partie, ce texte, examine ce que sont les modèles d\'évaluation intégrée du changement climatique et discute leurs buts principaux. La seccnde partie, plus appliquée, présente le modèle DIAM - Dynamics of Inertia and Adaptability Model. Il est utilisé pour discuter les paramètres socioéconomiques fondamentaux du problème: taux dáctualisation, taux de progrès technique, flexibilité des systèmes énergétiques, incertitude et cible ultime de concentration