极端天气和气候事件的变化

Changes in Weather and Climate Extremes

自1950年以来的观测证据表明,有些极端天气和气候事件已经发生了变化。全球尺度上,人为影响可能已经导致极端日最低和最高温度升高;由于平均海平面上升,人类活动可能已对沿海极端高水位事件的增加产生了影响;具有中等信度的是,人为影响已导致全球强降水增加;由于热带气旋历史记录的不确定性、缺乏对热带气旋与气候变化之间关联的物理机制的完整认识及热带气旋自然变率的程度,将可检测到的热带气旋活动变化归因于人为影响仅具有低信度。将单一的极端事件变化归因于人为气候变化具有挑战性。对极端事件变化预估的信度取决于事件的类型、区域和季节、观测资料的数量和质量、基本物理过程的认知水平及模式对其模拟的可靠性。

There is evidence from observations gathered since 1950 of changes in some weather and climate extremes. It is likely that anthropogenic influences have led to increase of extreme daily minimum and maximum temperatures on the global scale. It is likely that there has been an anthropogenic influence on increasing extreme coastal high water due to increase in mean sea level. There is medium confidence that anthropogenic influences have contributed to intensification of extreme precipitation on the global scale. The uncertainties in the historical tropical cyclone records, the incomplete understanding of the physical mechanisms linking tropical cyclone metrics to climate change, and the degree of tropical cyclone variability provide only low confidence for the attribution of any detectable changes in tropical cyclone activity to anthropogenic influences. Attribution of single extreme events to anthropogenic climate change is challenging. Confidence in projecting changes in the direction and magnitude of weather and climate extremes depends on many factors, including the type of extreme, the region and season, the amount and quality of observational data, the level of understanding of the underlying processes, and the reliability of their simulation in models.