《巴黎协定》未来气候情景下“一带一路”沿线区域气候舒适度预估

Changes in Thermal Comfort Conditions Throughout the Belt-and-Road Region in Response to Nationally Committed Emission Reductions Under the Paris Agreement

基于最新一代耦合气候模式比较计划全球气候模式的预估模拟结果,采用净有效温度指标,分析《巴黎协定》未来气候情景下“一带一路”沿线区域气候舒适度格局的变化。结果表明未来气候情景下研究区整体的热不舒适日数增多,冷不舒适日数减少,且二者存在明显的空间错配,舒适日数的增减则存在明显的空间分异。高纬度、高海拔寒冷区域(例如中东欧、西伯利亚和青藏高原)的冷不舒适日数大幅减少,舒适日数略有增加,低纬度温暖区域(例如东南亚和南亚)的热不舒适日数强烈增加,舒适日数明显减少。进一步结合人口分布来看,热不舒适天气的人口暴露度急剧增加,舒适和冷不舒适天气的人口暴露度减少,且前者的增量大大超过后两者的减量,导致“一带一路”沿线区域整体的气候舒适度水平呈下降态势。若在当前气候政策的基础上进一步加强减排力度,可以缓解这种不利影响。

Based on the global climate models participating in the sixth phase of the Coupled Model Intercomparison Project phase 6(CMIP6),we have adopted the Net Effective Temperature(NET),a comprehensive indicator of the integrative effect of temperature,humidity,and wind speed,to analyze the changes in the regional climate comfort pattern throughout the Belt-and-Road region in response to nationally committed emission reductions under the Paris Agreement.Our results indicate that,under future climate scenarios,the number of warm-uncomfortable days increased and the number of cold-uncomfortable days decreased in the region,and there was a clear spatial mismatch between the two signals.The changes in comfort days were characterized by strong spatial heterogeneity.The number of cold-uncomfortable days at mid to high altitudes decreases remarkably,which is the same as in Central and Eastern Europe,Siberia,and the QinghaiTibet Plateau,while the number of comfortable days increased by a moderate amount.The number of warmuncomfortable days at low latitudes increased significantly,such as in Southeast Asia and South Asia,while the number of comfortable days decreased substantially.Further analysis combined with the population distribution shows that the population which will be exposed to warm uncomfortable weather increases sharply,while the population which will be exposed to comfortable and cold uncomfortable weather decreases.The increase in the former significantly exceeds the decrease in the latter two;hence,the overall climatic comfort throughout the Belt-and-Road region deteriorates.This adverse effect can be mitigated if the emission reduction effort is further strengthened beyond the current climate policy.