期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2021
卷号：118
期号：44
DOI：10.1073/pnas.2107306118
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Significance
Snow avalanches represent a major threat in mountain environments, where they cause damage to critical infrastructure and claim hundreds of lives every year. Here, we document an unambiguous upslope migration of snow avalanches with climate change, a physical mechanism whose existence could previously not be demonstrated. In the Vosges Mountains, we show evidence that winter warming of +1.35 °C induced a sevenfold reduction in the number of avalanches, as well as a reduction of their magnitude and shortening of the avalanche season. These results show that low-to-medium elevation mountain ranges may serve as sentinels to anticipate future changes in snow processes and related risks in higher mountain environments and could thus help in the design of efficient adaptation strategies.
Snow is highly sensitive to atmospheric warming. However, because of the lack of sufficiently long snow avalanche time series and statistical techniques capable of accounting for the numerous biases inherent to sparse and incomplete avalanche records, the evolution of process activity in a warming climate remains little known. Filling this gap requires innovative approaches that put avalanche activity into a long-term context. Here, we combine extensive historical records and Bayesian techniques to construct a 240-y chronicle of snow avalanching in the Vosges Mountains (France). We show evidence that the transition from the late Little Ice Age to the early twentieth century (i.e., 1850 to 1920 CE) was not only characterized by local winter warming in the order of +1.35 °C but that this warming also resulted in a more than sevenfold reduction in yearly avalanche numbers, a severe shrinkage of avalanche size, and shorter avalanche seasons as well as in a reduction of the extent of avalanche-prone terrain. Using a substantial corpus of snow and climate proxy sources, we explain this abrupt shift with increasingly scarcer snow conditions with the low-to-medium elevations of the Vosges Mountains (600 to 1,200 m above sea level [a.s.l.
