2023: Weather and Climate Extremes Hitting the Globe with Emerging Features

Abstract

Globally, 2023 was the warmest observed year on record since at least 1850 and, according to proxy evidence, possibly of the past 100 000 years. As in recent years, the record warmth has again been accompanied with yet more extreme weather and climate events throughout the world. Here, we provide an overview of those of 2023, with details and key background causes to help build upon our understanding of the roles of internal climate variability and anthropogenic climate change. We also highlight emerging features associated with some of these extreme events. Hot extremes are occurring earlier in the year, and increasingly simultaneously in differing parts of the world (e.g., the concurrent hot extremes in the Northern Hemisphere in July 2023). Intense cyclones are exacerbating precipitation extremes (e.g., the North China flooding in July and the Libya flooding in September). Droughts in some regions (e.g., California and the Horn of Africa) have transitioned into flood conditions. Climate extremes also show increasing interactions with ecosystems via wildfires (e.g., those in Hawaii in August and in Canada from spring to autumn 2023) and sandstorms (e.g., those in Mongolia in April 2023). Finally, we also consider the challenges to research that these emerging characteristics present for the strategy and practice of adaptation.

根据全球平均温度记录, 2023年成为自1850年以来最热年份, 且根据代用记录, 这一年可能也是过去10万年以来最热的一年. 这一年破纪录的高温伴随着全球各地频发的极端天气气候事件. 本文回顾了2023年全球范围内发生的重大极端天气气候事件, 阐述了极端事件的事实经过、 产生的影响以及关键物理过程, 以促进更好地理解气候内部变率和人为气候变化的作用. 这些极端事件正在涌现出新的特征. 具体而言, 极端高温事件发生时间提前, 并且多地同时发生的高温现象在增加(如2023年7月北半球多地同时遭受热浪袭击). 强气旋活动显著加剧极端降水(如2023年7月的华北暴雨和9月的利比亚洪水). 一些地区(如加利福尼亚和非洲之角)经历了多年干旱向洪涝的转变. 此外, 频繁的野火(如2023年8月的夏威夷野火和加拿大从春季至秋季的野火)和沙尘暴(如2023年4月蒙古沙尘暴)等事件表明, 极端天气气候事件与生态系统的相互作用在加剧. 最后, 我们探讨了这些极端事件的新特征对于极端气候适应提出的新挑战.