Evaluating IPCC projections of global sea-level change from the pre-satellite era

With an acceleration of global sea-level rise during the satellite altimetry era (since 1993) firmly established, it is now appropriate to examine sea-level projections made around the onset of this time period. Here we show that the mid-range projection from the Second Assessment Report of the IPCC (1995/1996) was strikingly close to what transpired over the next 30 years, with the magnitude of sea-level rise underestimated by only ~1 cm. Projections of contributions from individual components were more variable, with a notable underestimation of dynamic mass loss from ice sheets. Nevertheless – and in view of the comparatively limited process understanding, modeling capabilities, and computational resources available three decades ago – these early attempts should inspire confidence in presently available global sea-level projections. Such multidecadal evaluations of past climate projections, as presented here for sea-level change, offer useful tests of past climate forecasts, and highlight the essential importance of continued climate monitoring.