Ice Sheet and Climate Processes Driving the Uncertainty in Projections of Future Sea Level Rise: Findings From a Structured Expert Judgement Approach

Bamber, J. L.; Oppenheimer, M.; Kopp, R. E.; Aspinall, W. P.; Cooke, R.M.

doi:10.1029/2022EF002772

Ice Sheet and Climate Processes Driving the Uncertainty in Projections of Future Sea Level Rise

Title

Ice Sheet and Climate Processes Driving the Uncertainty in Projections of Future Sea Level Rise: Findings From a Structured Expert Judgement Approach

Author

Bamber, J. L. (University of Bristol; Technische Universität München)
Oppenheimer, M. (Princeton University)
Kopp, R. E. (Rutgers University)
Aspinall, W. P. (University of Bristol; Aspinall and Associates)
Cooke, R.M. (TU Delft Applied Probability)

Date

2022

Abstract

The ice sheets covering Antarctica and Greenland present the greatest uncertainty in, and largest potential contribution to, future sea level rise. The uncertainty arises from a paucity of suitable observations covering the full range of ice sheet behaviors, incomplete understanding of the influences of diverse processes, and limitations in defining key boundary conditions for the numerical models. To investigate the impact of these uncertainties on ice sheet projections we undertook a structured expert judgement study. Here, we interrogate the findings of that study to identify the dominant drivers of uncertainty in projections and their relative importance as a function of ice sheet and time. We find that for the 21st century, Greenland surface melting, in particular the role of surface albedo effects, and West Antarctic ice dynamics, specifically the role of ice shelf buttressing, dominate the uncertainty. The importance of these effects holds under both a high-end 5°C global warming scenario and another that limits global warming to 2°C. During the 22nd century the dominant drivers of uncertainty shift. Under the 5°C scenario, East Antarctic ice dynamics dominate the uncertainty in projections, driven by the possible role of ice flow instabilities. These dynamic effects only become dominant, however, for a temperature scenario above the Paris Agreement 2°C target and beyond 2100. Our findings identify key processes and factors that need to be addressed in future modeling and observational studies in order to reduce uncertainties in ice sheet projections.

Subject

expert judgement
ice sheets
sea level rise
uncertainty

To reference this document use:

http://resolver.tudelft.nl/uuid:a26fb2f5-8c53-44f3-bbe3-cd6bb8bac626

DOI

https://doi.org/10.1029/2022EF002772

ISSN

2328-4277

Source

Earth's Future, 10 (10)

Part of collection

Institutional Repository