Changes to population-based emergence of climate change from CMIP5 to CMIP6
Changes to population-based emergence of climate change from CMIP5 to CMIP6
复制标题
DOI：
10.1088/1748-9326/aca91e
复制
发表时间：
2022-12
影响因子：
6.7
通讯作者：
H. Douglas;L. Harrington;M. Joshi;E. Hawkins;L. Revell;D. Frame
中科院分区：
文献类型：
--
作者：
H. Douglas;L. Harrington;M. Joshi;E. Hawkins;L. Revell;D. Frame
耦合模式比对项目第6阶段（CMIP6）模式集合预测，无论采取何种排放途径，气候变化在低纬度地区出现得最快、最强烈。就年平均气温的信噪比而言，这些模型在共享社会经济路径下比上一代模型在相应的代表性集中路径下更早、更强地出现。出现的空间格局也会在模型的不同代之间发生变化；在高排放情景下，本世纪中叶中非、南亚以及南美洲、西非、东亚和西欧部分地区的S/N低于以前的研究结果，但在大多数其他人口稠密地区较高。研究表明，这些全球和区域变化是由CMIP6整体中更高的有效气候敏感性、排放途径的变化、组分有效辐射强迫和模式世代之间区域尺度气候响应的变化共同引起的。我们还提出了CMIP6集合气候变化出现的第一个人口加权计算，量化了现在和未来暴露于异常温度增加程度的人数。我们的研究结果证实，从现在到许多国家提出的2050年净零排放目标之间的几十年里，气候变化相关影响的预期不平等。这些发现强调了同时在减缓和适应方面进行投资的重要性。
The Coupled Model Intercomparison Project Phase 6 (CMIP6) model ensemble projects climate change emerging soonest and most strongly at low latitudes, regardless of the emissions pathway taken. In terms of signal-to-noise (S/N) ratios of average annual temperatures, these models project earlier and stronger emergence under the Shared Socio-economic Pathways than the previous generation did under corresponding Representative Concentration Pathways. Spatial patterns of emergence also change between generations of models; under a high emissions scenario, mid-century S/N is lower than previous studies indicated in Central Africa, South Asia, and parts of South America, West Africa, East Asia, and Western Europe, but higher in most other populated areas. We show that these global and regional changes are caused by a combination of higher effective climate sensitivity in the CMIP6 ensemble, as well as changes to emissions pathways, component-wise effective radiative forcing, and region-scale climate responses between model generations. We also present the first population-weighted calculation of climate change emergence for the CMIP6 ensemble, quantifying the number of people exposed to increasing degrees of abnormal temperatures now and into the future. Our results confirm the expected inequity of climate change-related impacts in the decades between now and the 2050 target for net-zero emissions held by many countries. These findings underscore the importance of concurrent investments in both mitigation and adaptation.