Sea-Level Rise: From Global Perspectives to Local Services

Abstract

Coastal areas are highly diverse, ecologically rich, regions of key socio-economic activity, and are particularly sensitive to sea-level change. Over most of the 20th century, global mean sea level has risen mainly due to warming and subsequent expansion of the upper ocean layers as well as the melting of glaciers and ice caps. Over the last three decades, increased mass loss of the Greenland and Antarctic ice sheets has also started to contribute significantly to contemporary sea-level rise. The future mass loss of the two ice sheets, which combined represent a sea-level rise potential of ∼65 m, constitutes the main source of uncertainty in long-term (centennial to millennial) sea-level rise projections. Improved knowledge of the magnitude and rate of future sea-level change is therefore of utmost importance. Moreover, sea level does not change uniformly across the globe and can differ greatly at both regional and local scales. The most appropriate and feasible sea level mitigation and adaptation measures in coastal regions strongly depend on local land use and associated risk aversion. Here, we advocate that addressing the problem of future sea-level rise and its impacts requires (i) bringing together a transdisciplinary scientific community, from climate and cryospheric scientists to coastal impact specialists, and (ii) interacting closely and iteratively with users and local stakeholders to co-design and co-build coastal climate services, including addressing the high-end risks.

Drivers and Reversibility of Abrupt Ocean State Transitions in the Amundsen Sea, Antarctica

“…Tipping points are characterized by a hysteresis, that is, restoring the forcing to before the occurrence of the tipping point is not sufficient to restore the system to its original state. Identifying these tipping points precisely and linking them to climate projections would allow the effects of future rapid sea level rise to be anticipated and possibly mitigated (Durand et al, 2022;Hinkel et al, 2019).…”

Late Holocene coastal dynamics south of the Chanthaburi estuary, eastern Gulf of Thailand

“…On Holocene time scales, RSL changes in SE Asia resulted from a combination of eustatic, isostatic, and local factors such as human-induced subsidence and sediment supply (e.g., Kengkoom, 1992; Sinsakul, 1992; Tjia, 1996; Scoffin and Le Tissier, 1998; Horton et al, 2005; Oliver and Terry, 2019; Durand et al, 2022). For example, a Holocene maximum of +2.6 m at ca.…”

The evolution of 21st century sea-level projections from IPCC AR5 to AR6 and beyond

“…The IPCC authors and Technical Support Unit also collaborated with NASA to develop the NASA/IPCC Sea Level Projection Tool (https://sealevel.nasa.gov/ipcc-ar6-sea-level-projection-tool) to provide easy access to global and regional projections. As the need for more detailed sea-level information is becoming increasingly evident (e.g., Durand et al 2022;Hinkel et al 2019;Le Cozannet et al 2017b;, we discuss a couple of potential future research avenues which may help to further improve sea-level projections on a regional to local scale.…”