Wet bulb globe temperature (WBGT), a combined measure of temperature and humidity effects on thermal comfort, is used to define heat stress waves (HSWs). While emerging research has raised concerns on future changes in heat stress, for the first time, this study examines spatiotemporal changes in multiple HSW characteristics (intensity, duration, frequency, and cumulative mean intensity) in the 21st century under three emissions scenarios. It is the sustained nature of HSWs that impose more adverse impacts than extreme heat on a single day. HSWs are expected to be more intense, persistent, frequent, and influential due to anthropogenic influence. Models project the largest increases in multiple HSW characteristics will occur over the tropics and subtropics. The exception is maximum intensity, which displays a relative uniform increase over most global land areas. Analysis of regional population exposure to HSWs under different climate and socioeconomic scenarios emphasizes the importance of aggressive mitigation to minimize the potential impacts of HSWs. We further investigate how different regional HSW characteristics are projected to change relative to increasing global mean surface temperature (GMST). Our results confirm the varying rates and different trajectories at which regional HSWs change, independent of forcing pathway, strongly related to GMST. On both globally aggregated and regional scales, the maximum intensity and GMST are highly linearly associated, with an approximately 1:1 increase. However, the other three HSW characteristics are projected to change at a nonlinear rate per degree of GMST increase in general and display large regional variation in the rates of their changes.

中文翻译：

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21世纪热应力波全球和区域特征的变化

湿球温度（WBGT）是温度和湿度对热舒适性影响的综合度量，用于定义热应力波（HSW）。虽然新兴的研究引起了人们对未来热应力变化的担忧，但本研究首次考察了21世纪在三种排放情景下多种HSW特征（强度，持续时间，频率和累积平均强度）的时空变化。与单日极端高温相比，HSW的持续性造成的不利影响更大。由于人为因素的影响，HSW预计会更加激烈，持续，频繁和有影响力。模型预测，在热带和亚热带地区，多种HSW特征将出现最大的增长。最大强度除外 在全球大多数陆地上显示出相对均匀的增长。对不同气候和社会经济情景下区域居民接触高铁的影响的分析强调了积极缓解的重要性，以最大程度地减少高铁的潜在影响。我们进一步调查了如何预测不同区域的HSW特征相对于全球平均表面温度（GMST）的增加而变化。我们的结果证实了区域性高铁的变化速率和变化轨迹，与强迫途径无关，与GMST密切相关。在全球范围内和区域范围内，最大强度和GMST高度线性相关，大约增加1：1。然而，