Recent observations of elevated tree mortality following climate extremes, like heat and drought, raise concerns about climate change risks to global forest health. We currently lack both sufficient data and understanding to identify whether these observations represent a global trend toward increasing tree mortality. Here, we document events of sudden and unexpected elevated tree mortality following heat and drought events in ecosystems that previously were considered tolerant or not at risk of exposure. These events underscore the fact that climate change may affect forests with unexpected force in the future. We use the events as examples to highlight current difficulties and challenges for realistically predicting such tree mortality events and the uncertainties about future forest condition. Advances in remote sensing technology and greater availably of high-resolution data, from both field assessments and satellites, are needed to improve both understanding and prediction of forest responses to future climate change.

中文翻译：

---

气候变化对全球森林健康的风险：全球树木死亡率上升的意外事件的出现

最近观察到，高温和干旱等极端气候导致树木死亡率上升，引发了人们对气候变化对全球森林健康风险的担忧。我们目前缺乏足够的数据和理解来确定这些观察结果是否代表了树木死亡率增加的全球趋势。在这里，我们记录了生态系统中炎热和干旱事件后树木死亡率突然和意外升高的事件，这些生态系统以前被认为是耐受的或没有暴露的风险。这些事件强调了这样一个事实：气候变化未来可能会以意想不到的力量影响森林。我们以这些事件为例，强调当前实际预测此类树木死亡事件的困难和挑战以及未来森林状况的不确定性。需要遥感技术的进步以及更多地利用实地评估和卫星提供的高分辨率数据，以提高对森林对未来气候变化反应的理解和预测。