Strong Alpine glacier melt in the 1940s due to enhanced solar radiation

A 94‐year time series of annual glacier melt at four high elevation sites in the European Alps is used to investigate the effect of global dimming and brightening of solar radiation on glacier mass balance. Snow and ice melt was stronger in the 1940s than in recent years, in spite of significantly higher air temperatures in the present decade. An inner Alpine radiation record shows that in the 1940s global shortwave radiation over the summer months was 8% above the long‐term average and significantly higher than today, favoring rapid glacier mass loss. Dimming of solar radiation from the 1950s until the 1980s is in line with reduced melt rates and advancing glaciers.