loading page

A high-end estimate of sea-level rise for practitioners
  • +25
  • Roderik S. W. van de Wal,
  • Robert James Nicholls,
  • David Behar,
  • Kathleen Lynne Mcinnes,
  • Detlef Stammer,
  • Jason A. Lowe,
  • John Alexander Church,
  • Robert M. DeConto,
  • Xavier Fettweis,
  • Heiko Goelzer,
  • Marjolijn Haasnoot,
  • Ivan David Haigh,
  • Jochen Hinkel,
  • Benjamin P Horton,
  • T S James,
  • Adrian Jenkins,
  • Gonéri Le Cozannet,
  • Anders Levermann,
  • William H. Lipscomb,
  • Ben Marzeion,
  • Frank Pattyn,
  • Antony J Payne,
  • W. Tad Pfeffer,
  • Stephen Price,
  • Helene Seroussi,
  • S Sun,
  • W Veatch,
  • Kathleen White
Roderik S. W. van de Wal
Utrecht University

Corresponding Author:[email protected]

Author Profile
Robert James Nicholls
University of East Anglia
Author Profile
David Behar
San Francisco Public Utilities Commission
Author Profile
Kathleen Lynne Mcinnes
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Author Profile
Detlef Stammer
University Hamburg, Centrum für Erdsystemforschung und Nachhaltigkeit (CEN)
Author Profile
Jason A. Lowe
Met Office
Author Profile
John Alexander Church
Centre for Australian Weather and Climate Research
Author Profile
Robert M. DeConto
University of Massachusetts Amherst
Author Profile
Xavier Fettweis
University of Liège
Author Profile
Heiko Goelzer
NORCE Norwegian Research Centre, Bjerknes Centre for Climate Research, Bergen, Norway
Author Profile
Marjolijn Haasnoot
Deltares
Author Profile
Ivan David Haigh
University of Southampton
Author Profile
Jochen Hinkel
Global Climate Forum
Author Profile
Benjamin P Horton
NTU
Author Profile
T S James
19Natural Resources Canada, Geological Survey of Canada
Author Profile
Adrian Jenkins
BAS
Author Profile
Gonéri Le Cozannet
BRGM
Author Profile
Anders Levermann
Potsdam Institute for Climate Impact Research
Author Profile
William H. Lipscomb
National Center for Atmospheric Research
Author Profile
Ben Marzeion
University of Bremen
Author Profile
Frank Pattyn
Université Libre de Bruxelles
Author Profile
Antony J Payne
University of Bristol
Author Profile
W. Tad Pfeffer
University of Colorado Boulder
Author Profile
Stephen Price
Los Alamos National Laboratory (DOE)
Author Profile
Helene Seroussi
Dartmouth College
Author Profile
S Sun
Department of Geography and Environmental Sciences, Northumbria University
Author Profile
W Veatch
US Army Corps of Engineers
Author Profile
Kathleen White
United States Army Corps of Engineers
Author Profile

Abstract

Sea-level rise (SLR) is a long-lasting consequence of climate change because global anthropogenic warming takes centuries to millennia to equilibrate. SLR projections based on climate models support policy analysis, risk assessment and adaptation planning today, despite their large uncertainties. The central range of the SLR distribution is estimated by process-based models. However, risk-averse practitioners often require information about plausible future conditions that lie in the tails of the SLR distribution, which are poorly defined by existing models. Here, a community effort combining scientist and practitioners, builds on a framework of discussing physical evidence to quantify high-end global SLR for practice. The approach is complementary to the IPCC AR6 report and provides further physically plausible high-end scenarios. High-end estimates for the different SLR components are developed for two climate scenarios at two timescales. For global warming of +2 ˚C in 2100 (SSP1-2.6) relative to pre-industrial values our high-end global SLR estimates are up to 0.9 m in 2100 and 2.5 m in 2300. Similarly, for +5 ˚C (SSP5-8.5) we estimate up to 1.6 m in 2100 and up to 10.4 m in 2300. The large and growing differences between the scenarios beyond 2100 emphasize the long-term benefits of mitigation. However, even a modest 2 ˚C warming may cause multi-meter SLR on centennial time scales with profound consequences for coastal areas. Earlier high-end assessments focused on instability mechanisms in Antarctica, while we emphasize the timing of ice-shelf collapse around Antarctica, which is highly uncertain due to low understanding of the driving processes.