Climate change is seriously affecting the cryosphere in
terms, for example, of permafrost thaw, alteration of rain ∕ snow ratio, and
glacier shrinkage. There is concern about the increasing number of rockfalls
at high elevation in the last decades. Nevertheless, the exact role of
climate parameters in slope instability at high elevation has not been fully
explored yet. In this paper, we investigate 41 rockfalls listed in different
sources (newspapers, technical reports, and CNR IRPI archive) in the
elevation range 1500–4200 m a.s.l. in the Italian Alps between 1997 and 2013
in the absence of an evident trigger. We apply and improve an existing
data-based statistical approach to detect the anomalies of climate
parameters (temperature and precipitation) associated with rockfall
occurrences. The identified climate anomalies have been related to the
spatiotemporal distribution of the events. Rockfalls occurred in
association with significant temperature anomalies in 83 % of our case
studies. Temperature represents a key factor contributing to slope failure
occurrence in different ways. As expected, warm temperatures accelerate
snowmelt and permafrost thaw; however, surprisingly, negative anomalies are
also often associated with slope failures. Interestingly, different regional
patterns emerge from the data: higher-than-average temperatures are often
associated with rockfalls in the Western Alps, while in the Eastern Alps slope
failures are mainly associated with colder-than-average temperatures