Levy, R.H.; Patterson, M.O.; Kulhanek, D.K.; van de Flierdt, T.; Horgan, H.; Dunbar, G. 2025 Sensitivity of the West Antarctic Ice Sheet to 2°C – SWAIS2C: science implementation and logistics plan. Lower Hutt, NZ: GNS Science. GNS Science miscellaneous series 142. 92 p.; doi: 10.21420/DRD3-AP98
Abstract
The West Antarctic Ice Sheet (WAIS) presently holds enough ice to raise global sea level by ~5 m if completely melted. The unknown response of the WAIS to future warming remains a significant challenge for numerical models in quantifying predictions of future sea-level rise. Sea-level rise is one of the clearest planet-wide signals of human-induced climate change. The Sensitivity of the West Antarctic Ice Sheet to a Warming of 2°C (SWAIS2C) Project aims to understand past and current drivers and thresholds of WAIS dynamics to improve projections of the rate and size of ice sheet changes under a range of elevated greenhouse gas levels in the atmosphere, as well as the associated average global temperature scenarios to and beyond the +2°C target of the Paris Climate Agreement. Despite efforts through previous land- and ship-based drilling on and along the Antarctic margin, unequivocal evidence of major WAIS retreat or collapse and its causes has remained elusive. To address this gap, researchers, engineers and logistics providers representing 10 countries have established the SWAIS2C Project, an international partnership comprised of geologists, glaciologists, oceanographers, geophysicists, microbiologists, climate and ice-sheet modellers and engineers, outlining specific research objectives and logistical challenges associated with the recovery of Neogene and Quaternary geological records from the West Antarctic interior adjacent to the Kamb Ice Stream and at Crary Ice Rise. New geophysical surveys at these locations have identified drilling targets in which new drilling technologies will allow for the recovery of up to 200 m of sediments and sedimentary rock beneath the ice sheet. Sub-ice-shelf records have so far proven difficult to obtain but are critical to better constrain marine ice-sheet sensitivity to past and future increases in global mean surface temperature up to 2°C above pre-industrial levels. Thus, the scientific and technological advances developed through this programme will enable us to test whether WAIS collapsed during past intervals of warmth and determine its sensitivity to a +2°C global warming threshold. This document outlines the scientific background rationale, as well as the scientific, drilling operations and logistics implementation plan for the project (auths)
