Forecasted weakening of Atlantic overturning circulation could amplify future relative sea-level rise in the Mediterranean: A review of climate and tide-gauge data links

• Published in: Earth-Science Reviews
• Main Authors: Marriner, Nick, Kaniewski, David, Pourkerman, Majid, Vacchi, Matteo, Melini, Daniele, Seeliger, Martin, Morhange, Christophe, Spada, Giorgio
• Other Authors: Théoriser et modéliser pour aménager (UMR 6049) (ThéMA), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté COMUE (UBFC)-Université Bourgogne Franche-Comté COMUE (UBFC), Travaux et recherches archéologiques sur les cultures, les espaces et les sociétés (TRACES), École des hautes études en sciences sociales (EHESS)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Ministère de la Culture et de la Communication (MCC)-Institut national de recherches archéologiques préventives (Inrap)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Geological Survey of Iran, Dipartimento di Scienze della Terra Pisa, University of Pisa - Università di Pisa, Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Roma (INGV), Istituto Nazionale di Geofisica e Vulcanologia, Goethe-Universität Frankfurt am Main, Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Archéologie et Philologie d'Orient et d'Occident (AOROC), École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Département des Sciences de l'Antiquité - ENS Paris (DSA ENS-PSL), École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL), Dipartimento di Fisica e Astronomia Bologna, Alma Mater Studiorum Università di Bologna = University of Bologna (UNIBO)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: Tide gauge; Climate; Mediterranean; North Atlantic; Coasts; Relative sea-level change; [SDE.MCG]Environmental Sciences/Global Changes; [SDE]Environmental Sciences
• Online Access: https://hal.science/hal-04125542; https://hal.science/hal-04125542/document; https://hal.science/hal-04125542/file/Marriner,%20Kaniewski%20et%20al_Earth%20science%20reviews_2023%20%281%29.pdf; https://doi.org/10.1016/j.earscirev.2023.104456

International audience Sea-level rise is one of the most significant and perceptible consequences of global warming because it affects natural environments and coastal anthroposcapes at human timescales, particularly in sediment-starved littoral contexts. Within this framework, improvements in understanding the projection of sea-level rise require better knowledge of regional changes. Here we focus on the recent sea-level history of the Mediterranean Sea, an area characterized by a densely populated coast and where climate variability is larger, and the rate of sea-level rise higher than the global average. We produce a spatially-averaged Mediterranean relative sea-level (RSL) time series, based on 138 tide-gauge records, stretching back to the late 1800s, indicating that Mediterranean RSL has risen by ∼24 cm in the past ∼140 years. At interdecadal timescales and beyond, we find that Mediterranean relative sea-level rising rates (RSLRR) are significantly influenced by the strength of the Atlantic Multidecadal Oscillation (AMO) and the Atlantic Meridional Overturning Circulation (AMOC). Climate-model predictions of a weakened Atlantic overturning circulation in the coming decades, slowing and diminishing North Atlantic heat transport, has the potential to accentuate Mediterranean rising rates, with significant implications for the basin's coastal societies, infrastructure and economies. We conservatively estimate that a 0.1 °C decrease in AMO sea surface temperatures can accentuate Mediterranean RSLRR by up to −0.61 ± 0.5 mm yr−1. Future coastal management and adaptation policies must assimilate these findings into local/regional-scale impact and vulnerability assessments.