气候变化综合评估模型研究新进展

Progress of integrated assessment models for climate policy

本文在总结全球29个典型的气候变化综合评估模型(integrated assessment models,简称IAM)的基础上,围绕模型框架,不确定性,公平性,技术进步和减排机制等五个关键科学问题,系统总结并评述了气候变化综合评估模型的新进展.气候变化综合评估模型主要的模型框架有最优化模型,可计算一般均衡模型和模拟模型等三类.针对气候变化不确定性,气候变化综合评估建模中需要解决气候变化影响的概率分布,人类对气候变化的风险厌恶程度,人类对社会福利的时间偏好等问题.在代际公平性方面,伦理派支持较低的贴现率,在气候政策上主张立即大幅减排;市场派支持较高的贴现率,在气候政策上主张渐进式采取行动.在区域公平性方面,应当给予欠发达地区高于发达地区的社会福利权重.综合评估模型对技术进步的处理有从外生到内生的趋势,技术进步内生的主要途径包括直接价格诱导,研发诱导和学习诱导三种类型.在减排机制方面,从成本效益角度分析的学者普遍认为价格机制比数量机制更有效.

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 deseriptionist supports the high discount rate and ＂step- by-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.