Spatiotemporal Projections of Global Sea-Level Rise: A High-Resolution CMIP۶-Based Analysis for ۲۰۱۵–۲۰۵۰

Accurate and high-resolution projections of sea-level rise (SLR) are critical for assessing regional climate risks and formulating adaptation strategies. This study presents a high-resolution spatiotemporal analysis of global SLR from ۲۰۱۵ to ۲۰۵۰, leveraging the latest CMIP۶ model ensemble under moderate emission scenarios. Our findings project a global mean sea-level rise (GMSLR) of ۸۳.۷ mm, driven predominantly by thermal expansion and ice-sheet melt. The spatial pattern is profoundly heterogeneous, characterized by a pronounced dipole: maximum rises exceeding ۱۷۸ mm are identified in subtropical gyres due to steric effects, while significant sea-level fall occurs near melting ice sheets (down to -۲۳۷.۵ mm) due to gravitational and glacial isostatic adjustment fingerprints. This non-uniformity exposes -۸۹% of global coastlines to rates exceeding ۳۰ mm/decade, drastically increasing inundation risks for low-lying regions and megacities. Our results underscore the urgency for policy-relevant, localized adaptation planning that accounts for these fine-scale SLR disparities and the potential for higher upper-end estimates due to ice-sheet instability.

کلیدواژه ها:

Sea level rise projections ، CMIP۶ ، Spatiotemporal heterogeneity ، Coastal vulnerability