Emergent decadal predictability in Antarctic contribution to sea-level rise

Area of Science:

• Glaciology
• Climate Science
• Sea-Level Rise Research

Background:

• Future Antarctic ice loss contributes significantly to global sea-level rise, but involves substantial uncertainties.
• Existing ice-sheet models are crucial for projecting future sea-level changes.

Purpose of the Study:

• To assess the near-term predictability of Antarctic ice loss and its impact on sea-level rise.
• To identify key feedback mechanisms influencing long-term sea-level rise projections.
• To guide future ice-sheet model development for reducing uncertainty.

Main Methods:

• Analysis of ice-sheet models used in the Intergovernmental Panel on Climate Change Sixth Assessment Report.
• Evaluation of model performance in reproducing present-day ice-mass loss.
• Investigation of model behavior across different emission pathways and complexities.

Main Results:

• Sea-level rise rate in 2025 is a strong predictor of rates for several decades, irrespective of emission scenarios or model complexity.
• This predictability holds across all considered models, including high-impact scenarios.
• Predictability diminishes by the late 21st century due to emerging feedbacks like marine ice-sheet retreat.

Conclusions:

• Ice-sheet models accurately reflecting current ice loss offer reliable near-term sea-level rise projections for planning up to mid-century.
• Understanding feedback mechanisms is crucial for bridging the gap between near-term predictability and long-term projections.
• Prioritizing model development to resolve long-term sea-level rise uncertainty is essential.