据介绍，夏季极端温度会对人类和生物圈产生巨大影响，极端高温的增加是气候变化最明显的症状之一。人们提出了多种机制来预测升温速度比典型夏季更快的极端天气，但目前尚不清楚这种情况是否正在发生。
研究表明，在观测和历史气候模型模拟中，从1959-2023年，在每个半球和热带地区，夏季最热的日子以与全球中值相同的速度变暖。相比之下，最冷的夏季天气变暖的速度比全球平均水平的中值要慢，这一信号在28个CMIP6模型的262个模拟中都没有得到模拟。研究观测到的冷尾延伸表明，尽管缺乏炎热天气放大，但观测到的夏季温度已变得更加多变。
与中值相比，冷热极值的年际变率和增温趋势，可以从基于净地表辐射和蒸发分数变化的地表能量平衡角度来解释。研究结果强调，预计未来将出现热带炎热天气放大(2024-2099年，SSP3-7.0情景)，而北半球极端高温预计将继续遵循中值。
附：英文原文
Title: The pace of change of summertime temperature extremes
Author: McKinnon, Karen A., Simpson, Isla R., Williams, A. Park
Issue&Volume: 2024-10-7
Abstract: Summer temperature extremes can have large impacts on humans and the biosphere, and an increase in heat extremes is one of the most visible symptoms of climate change. Multiple mechanisms have been proposed that would predict faster warming of heat extremes than typical summer days, but it is unclear whether this is occurring. Here, we show that, in both observations and historical climate model simulations, the hottest summer days have warmed at the same pace as the median globally, in each hemisphere, and in the tropics from 1959 to 2023. In contrast, the coldest summer days have warmed more slowly than the median in the global average, a signal that is not simulated in any of 262 simulations across 28 CMIP6 models. The observed stretching of the cold tail indicates that observed summertime temperatures have become more variable despite the lack of hot day amplification. The interannual variability and trend in the warming of both hot and cold extremes compared to the median can be explained from a surface energy balance perspective based on changes in net surface radiation and evaporative fraction. Tropical hot day amplification is projected to emerge in the future (2024–2099, SSP3-7.0 scenario), while Northern Hemisphere heat extremes are expected to continue to follow the median.
DOI: 10.1073/pnas.2406143121
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2406143121