气候变化背景下全球极端天气事件GDP损失率评估

本文通过研究不同碳排放情景下未来70年全球气温上升的可能性,量化了极端天气事件对全球GDP可能造成的损失.首先,本文采用DICE模型评估了未来每十年全球GDP年损失率的离散概率分布;然后利用本文提出的一种新的广义对数正态分布函数,对未来每十年全球GDP年损失率的概率分布进行了拟合;最后,通过计算极端天气事件发生频率分别小于0.5%, 1%, 5%情形时GDP损失率的范围,讨论了不同碳排放情景下GDP损失率尾部分布的差异,分析了温度变化对损失率的影响.结果表明:在不同碳排放情景下,全球年GDP损失率的概率密度曲线尾部均表现出小概率大损失的特征,本研究可为有关机构做好气候变化背景下巨灾风险损失的量化分析提供依据.

Damage assessment of extreme weather events under climate change

This study is an attempt to calculate the economic damages from 2020 to 2090 with Nordhaus's DICE model using the probabilities of global mean surface temperature changes from 2020 to 2090 under RCPs and A1B. Also, probability cumulative density curves are fitted according to the improved lognormal distribution, then probability density curves are obtained. Furthermore, we analyze the tendencies of these curves, especially the fatten tails. After that, economic damages are calculated under warming probabilities of 5%、1%、0.5% for each decade from 2020 to 2090, and effects of temperature imposed on loss rate are also analyzed. The results show that under the different scenarios of carbon emissions, the tail of the probability density curve of the global annual GDP loss rate shows a character of small probability of large loss. In conclusion, we offer more possible damage estimates in probabilistic perspective under uncertain warming events in order to provide a better understanding of risk aversion with a rapid warming world.