Progress of integrated assessment models for climate policy

Based on 29 existing climate change integrated assessment models (IAM), this paper discusses the progress of integrated assessment models for climate policy with five key aspects in IAMs including model structure, uncertainty, equity, technical change and abatement mechanism. There are three main categories in IAMs including optimization models, computable general equilibrium (CGE) models and simulation models. In order to model the uncertainties in climate change, IAMs in the future need to answer questions such as the probability distribution of the effects of climate change, the degree to which human society is risk averse and the rate at which human society discounts future benefits and costs relative to those in the present. As for the intergenerational equity, prescriptionist supports the low discount rate and immediate actions in climate policies, while descriptionist supports the high discount rate and "stepby-step" actions in climate policies. As for the international equity, IAMs should place greater welfare weights on the low-income regions. IAMs have the tendency to make technical change endogenous by three approaches including direct price-induced, R & D-induced and learning-induced. As for the GHG emission reduction mechanism, most researchers who use the cost-benefit analysis consider that quantity-based mechanisms are more efficient than price-based mechanisms.