Literature Review of Integrated Impact Assessment Models of Climate Change with Emphasis on Damage Functions

We review the literature on the impact assessment models currently used in the climate change debate. From among these we select some relevant models, highlight their important features and identify how climate change damages are treated. A common feature of the treatment of climate change damages within the existing models seems to be the significant degree of subjectivity involved in the choice of parameters, functional forms and the potential damages in case of temperature changes above the current predicted (low) levels. This is in part due to the small number of studies available from which we can estimate climate change damages, which forces researchers to extrapolate, from a small set of figures, damage for higher temperature changes and for regions of the world other than those where the original studies were undertaken. Thus, uncertainty surrounding damage functions is inevitably high.