a, Mean specific glacier mass balance by glacier size class. The fact that this graph is relatively flat suggests that the differing mass balance between small glaciers and larger glaciers is not a driver for small glaciers (and by extension missing glaciers) contributing a large amount to SLE mass loss relative to their current ice mass. Glacier size does not strongly affect mean specific mass balance, and this weak dependence is also shown in observations from the literature25. b, Mean proportion of 1901 mass lost between 1901 and 2015 as a function of glacier size class. The smallest glaciers that exist in 2015 typically lost almost all of their 1901 mass, with the proportion dropping consistently as 2015 glacier size increases, up to the largest glaciers in 2015, which have seen an average of less than 10% of their mass disappear since 1901.