Toward an Ice‐Free Mountain Range: Demise of Pyrenean Glaciers During 2011–2020

Abstract

International audienceGlacier mass balance evolution depends on snow accumulation and snow, firn and ice melt during the cold and warm seasons respectively and is thus considered a reliable indicator of climate fluctuations (Braithwaite & Hughes, 2020). The Little Ice Age (LIA, between the 14th and 19th centuries) represents the last global advance phase for the majority of mountain glaciers around the world (Solomina et al., 2016). Since then, the decline of glaciers has been almost continuous, only interrupted by short stabilization periods (Zemp et al., 2015). Several studies identify the 1980s as a "tipping point in global glacier evolution," followed by accelerated glacier shrinkage (Beniston et al., 2018; Huss & Hock, 2018). Very small glaciers (<0.5 km 2) predominate in number in the northern hemisphere mountain ranges at temperate latitudes, since more than 80% of glaciers in these mountains are beneath this area threshold (Huss & Fischer, 2016). Shrinkage of very small glaciers occurred more rapidly by the late 20 th and early 21 st centuries than in earlier decades (Bahr & Radić, 2012; Parkes & Marzeion, 2018). This fast shrinkage is explained by their generally low accumulation area ratio, which is mainly driven by the observed globa