This study examines past and present accumulation rates of the West Antarctic Ice Sheet (WAIS) to improve our understanding of the ice sheet’s evolution and its contribution to sea-level rise. The research team used a pervasive ice-penetrating radar reflector dated to 4.72 ka BP, called the “4.72 ka IRH”, to infer accumulation rates across a large region covering 30% of the WAIS. By comparing their results with modern climate reanalysis models and observational data, the researchers discovered that accumulation rates during the mid-Holocene were 18% higher than modern rates over the Amundsen–Weddell–Ross Divide. This finding suggests that the WAIS Divide ice core is spatially representative of the wider West Antarctic region and can be used as a reliable climate forcing for regional and continental ice-sheet modelling studies to generate more realistic predictions of the WAIS’s past and future contribution to sea-level rise.