Constraining the contribution of the Antarctic Ice Sheet to Last Interglacial sea level

Abstract

Polar temperatures during the Last Interglacial [LIG; ~129 to 116 thousand years (ka)] were warmer than today, making this time period an important testing ground to better understand how ice sheets respond to warming. However, it remains debated how much and when the Antarctic and Greenland ice sheets changed during this period. Here, we present a combination of new and existing absolutely dated LIG sea-level observations from Britain, France, and Denmark. Because of glacial isostatic adjustment (GIA), the LIG Greenland ice melt contribution to sea-level change in this region is small, which allows us to constrain Antarctic ice change. We find that the Antarctic contribution to LIG global mean sea level peaked early in the interglacial (before 126 ka), with a maximum contribution of 5.7 m (50th percentile, 3.6 to 8.7 m central 68% probability) before declining. Our results support an asynchronous melt history over the LIG, with an early Antarctic contribution followed by later Greenland Ice Sheet mass loss.

East Antarctic warming forced by ice loss during the Last Interglacial

“…In general, the best agreement is found in the ice loss only experiments (SL4.1 and SL7.1), while a poorer agreement is found when introducing meltwater both separately (FW4.1 and FW7.1) and combined with the ice loss (COMB4.1 and COMB7.1). These data suggest that, in the context of uncertain timing of Antarctic melting at the LIG 5 , 10 , that the peak meltwater pulse in the Southern Ocean did not occur simultaneously with the warmest SST anomalies, since meltwater tends to strongly cool the surface of the Southern Ocean.…”

“…The Greenland ice sheet is estimated to have contributed 0.4 to 4.4 m sea-level equivalent (SLE) 6 , 7 compared with 1 to 7 m SLE for Antarctica 5 , 8 , 9 . A recent study suggests the AIS contributed 5.7 m SLE of sea level rise, with a likely range of 3.6 to 8.7 m (68% probability) 10 . However, the evolution of these ice sheets and their associated climate feedbacks are not well understood, motivating further examination with physical climate models.…”

The timing and magnitude of the British–Irish Ice Sheet between Marine Isotope Stages 5d and 2: implications for glacio‐isostatic adjustment, high relative sea levels and ‘giant erratic’ emplacement

“…These OSL ages have stimulated renewed interest in dating the supposed interglacial raised beaches in southern Britain and the Channel Islands. Whilst a systematic OSL dating campaign remains to be undertaken, a suite of 25 recently published OSL ages from raised beaches in South Wales, Sussex, the Isle of Wight, Jersey, Normandy and Cornwall, including the Godrevy raised beach, the type-site of the Godrevy Sands and Gravels, previously reported as being MIS5e in age based on aminostratigraphic data (Bowen et al, 1985;James, 1995;Scourse, 1996), have generated data consistent with the Last Interglacial attribution (Barnett et al, 2023). The weighted mean for the Cornish data (seven measurements) is 119 ± 3 ka, the Devon result is 116 ± 9 ka, Jersey 121 ± 14 ka, Wales weighted mean (two measurements) 121 ± 8 ka, Isle of Wight 115 ± 10 ka, Sussex (three measurements) ranging from 121 ± 12 to 124 ± 10 ka, and Normandy weighted mean (three measurements) 118 ± 7 ka.…”

Unveiling the Influence of Subjective Norms on Flood Preparedness Among Household Renters: The Moderating Effect of Trust in Public Protection

“…Climate change has drastically altered the lives of people in the world through natural disasters, especially floods. Climate change has the potential to enhance the frequency and intensity of natural disasters utilizing diverse mechanisms, including heightened temperatures, alterations in precipitation patterns, rising sea levels, and shifts in ecosystems (Barnett et al, 2023). The United Nations Office for Disaster Risk Reduction (2013) states that global economic damages exceeding $40 billion occur yearly due to floods, impacting around 250 million individuals.…”