We compare 14 glacial isostatic adjustment (GIA) models from different authors to assess
how well the GIA effect could be removed from space geodetic data, such as those of the
Gravity Recovery and Climate Experiment (GRACE) satellites, to study climate related and
other mass changes within the Earth system. Direct comparisons of model outputs confirm
unacceptably large discrepancies among models. Here we use two approximate relations
within any GIA model without rotational feedback discovered by Wahr et al.(1995), ie, an …