Rockfall in high-mountain regions is thought to be changing due to accelerating climate warming and permafrost degradation, possibly resulting in enhanced activity and larger volumes involved in individual falls. Yet the systematic lack of long-term observations of rockfall largely hampers an in-depth assessment of how activity may have been altered by a warming climate. Here we compile a continuous time series from 1920 to 2020 of periglacial rockfall activity using growth-ring records from 375 trees damaged by past rockfall at Täschgufer (Swiss Alps). We show that the ongoing warming favours the release of rockfall and that changes in activity correlate significantly with summer air temperatures at interannual and decadal timescales. An initial increase in rockfall occurred in the late 1940s to early 1950s following early twentieth century warming. From the mid-1980s, activity reached new and hitherto unprecedented levels. This long-term record of rockfall activity can help to inform the design of vital mitigation and risk reduction measures in inhabited mountain environments.

人们认为，由于气候变暖和永久冻土退化加速，高山区的落石正在发生变化，可能导致活动增强和个别落石量增加。然而，对落石的长期观测的系统性缺乏在很大程度上阻碍了对气候变暖可能如何改变活动的深入评估。在这里，我们利用 Täschgufer（瑞士阿尔卑斯山）过去因落石而受损的 375 棵树的年轮记录，编制了 1920 年至 2020 年冰缘落石活动的连续时间序列。我们表明，持续变暖有利于落石的释放，并且活动的变化与年际和年代际时间尺度的夏季气温显着相关。随着二十世纪初气候变暖，落石量最初增加发生在 20 世纪 40 年代末至 50 年代初。从 20 世纪 80 年代中期开始，活动达到了前所未有的新水平。这种落石活动的长期记录有助于为有人居住的山区环境中重要的缓解和降低风险措施的设计提供信息。