ABSTRACT

Anthropogenic emissions of greenhouse gases are warming the Earth. It is likely that the greatest impacts of climate change on human and natural systems will come from increasingly frequent and severe extreme weather and climate events. Some increases in such extremes are already being detected, and this trend is projected to continue as Earth warms. Here we review the overarching climate drivers of increases in extreme weather and address the context in which extremes occur and the challenges of projecting future changes. The observational evidence for climate-driven increases in extremes and the implications of model projections are reviewed for heat and drought and several types of storms: tropical cyclones, midlatitude storms, and severe local weather, focusing on those changes most relevant to the continental United States. We emphasize the overall observed and modeled trends in extreme weather in which we have the greatest confidence, because they are consistent with our fundamental understanding of weather and climate. Despite remaining uncertainty about many details, especially in model-based projections, the signal of increasing extremes is sufficiently clear that it demands a robust human response, in limiting future emissions of greenhouse gases and in making our human systems more resilient to further changes that are inevitable as Earth continues to warm.

Implications: By placing observed and projected changes in extreme weather in the context of our fundamental understanding of physics and statistics, this review makes it clear that these are significant and impactful changes that demand a robust human response.

摘要

人为排放的温室气体正在使地球变暖。气候变化对人类和自然系统的最大影响很可能来自日益频繁和严重的极端天气和气候事件。已经检测到此类极端事件的一些增加，并且随着地球变暖，预计这种趋势将持续下去。在这里，我们回顾了极端天气增加的总体气候驱动因素，并讨论了极端事件发生的背景以及预测未来变化的挑战。气候驱动的极端事件增加的观测证据以及模型预测对高温和干旱以及几种类型风暴的影响进行了审查：热带气旋、中纬度风暴和恶劣的当地天气，重点关注与美国大陆最相关的那些变化. 我们强调我们最有信心的极端天气的整体观测和模拟趋势，因为它们与我们对天气和气候的基本理解是一致的。尽管在许多细节方面仍然存在不确定性，尤其是在基于模型的预测中，但极端事件增加的信号已经足够清楚，需要人类做出强有力的反应，以限制未来的温室气体排放，并使我们的人类系统更能适应正在发生的进一步变化。随着地球继续变暖，这是不可避免的。

意义：通过将观测到的和预测的极端天气变化置于我们对物理学和统计学的基本理解的背景下，这篇评论清楚地表明这些是需要人类做出强有力反应的重大且有影响的变化。