A Probabilistic Estimate of Mid-Holocene Sea Level
Abstract
Rising sea level in the coming decades poses a major threat to coastal communities, yet projecting the relative and global mean sea level response to prolonged warming is complex. Lack of modern analogues for future climatic behavior has turned attention to episodes in the recent geologic past that can yield insight into how Earths climate system reacts to temperature forcing. Recent evidence suggests the Greenland and Antarctic ice sheets may have retreated past their present-day extents during the mid-Holocene (~8-5 ka), then readvanced until the pre-industrial. These findings have turned attention to the mid-Holocenewhen northern hemispheric temperatures may have been up to 4 degrees hotter than preindustrial levelsas a partial analogue for future warming scenarios. Here we present a new probabilistic estimate of mid-Holocene global mean sea level (GMSL). We construct an ensemble of global ice sheet reconstructions for the last 80 kyr that spans a range of possible mid-Holocene GMSL scenarios. We predict relative sea level from each model accounting for glacial isostatic adjustment and using a range of solid earth structures. We then compare these predictions to a global database of ~22,000 sea-level indicators from the last 60,000 years, and use data-model fits to weigh the GMSL curves from each ice model. The constraints placed on the mid-Holocene global mean sea level budget enable a new estimate of post-glacial Antarctic ice volume, and shed light on climate dynamics during this critical interval in Earths recent history.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFMPP45B1103C