Risks from Climate Extremes Change Differently from 1.5°C to 2.0°C Depending on Rarity
Risks from Climate Extremes Change Differently from 1.5°C to 2.0°C Depending on Rarity
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DOI：
10.1002/2018ef000813
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发表时间：
2018-05-01
期刊：
影响因子：
8.2
通讯作者：
Anderson, K. J.
中科院分区：
文献类型：
--
作者：
Kharin, V. V.;Flato, G. M.;Anderson, K. J.
《联合国气候变化框架公约》缔约方同意将“全球平均气温比工业化前水平的升幅控制在远低于2摄氏度的范围内，并努力将气温升幅限制在1.5摄氏度以内。“不同变暖极限的成本和效益的比较需要了解不同变暖极限之间的风险如何变化。由于风险的变化往往与局部或区域极端气候的预测变化引起的暴露变化有关，因此我们分析了不同变暖极限下极端日温度和极端日降水量风险的差异。我们表明，全球变暖2摄氏度将导致极端事件概率的变化远远大于全球变暖1.5摄氏度。例如，在全球陆地面积上，在当前气候中平均每20年发生一次的极端温暖事件的概率预计在1.5摄氏度和2.0摄氏度的变暖水平下分别增加130%和340%（中值）。此外，概率的相对变化在更罕见、更极端的事件中更大，这意味着风险评估需要仔细考虑出现脆弱性的极端事件阈值。
Parties to the United Nations Framework Convention on Climate Change have agreed to hold the "increase in global average temperature to well below 2 degrees C above preindustrial levels and to pursue efforts to limit the temperature increase to 1.5 degrees C." Comparison of the costs and benefits for different warming limits requires an understanding of how risks vary between warming limits. As changes in risk are often associated with changes in exposure due to projected changes in local or regional climate extremes, we analyze differences in the risks of extreme daily temperatures and extreme daily precipitation amounts under different warming limits. We show that global warming of 2 degrees C would result in substantially larger changes in the probabilities of the extreme events than global warming of 1.5 degrees C. For example, over the global land area, the probability of a warm extreme that occurs once every 20 years on average in the current climate is projected to increase 130% and 340% at the 1.5 degrees C and 2.0 degrees C warming levels, respectively (median values). Moreover, the relative changes in probability are larger for rarer, more extreme events, implying that risk assessments need to carefully consider the extreme event thresholds at which vulnerabilities occur.