The University of Southampton
University of Southampton Institutional Repository

A new approach to projecting 21st century sea-level changes and extremes

A new approach to projecting 21st century sea-level changes and extremes
A new approach to projecting 21st century sea-level changes and extremes
Future increases in flooding potential around the world’s coastlines from extreme sea level events is heavily dependent on projections of future Global Mean Sea Level (GMSL) rise. Yet the two main approaches for projecting 21st century GMSL rise – i.e., process-based versus semi-empirical – give inconsistent results. Here, a novel hybrid approach to GMSL projection, containing a process-based thermosteric contribution and a semi-empirical ice-melt contribution, is embedded within a conceptual Earth System Model (ESM). The ESM is run 10 million times with random perturbations to multiple parameters, and future projections are made only from the simulations that are historically consistent. The projections from our hybrid approach are found to be consistent with the dominant process-based GMSL projections from the Climate Model Intercomparison Project phase 5 (CMIP5) ensemble, in that our future ensemble-mean projections lie within ±2 cm of CMIP5 for the end of the 21st century when CMIP5 simulated histories are used to constrain our approach. However, when observations are used to provide the historic constraints for our hybrid approach, we find higher ice-melt sensitivity and additional ensemble-mean GMSL rise of around 13 to 16 cm by the end of the century. We assess the impact of this additional GMSL rise, projected from observation-consistency, on the increase in frequency of extreme sea level events for 220 coastal tide-gauge sites. Accounting for regional effects, we infer a 1.5 to 8 times increase in the frequency of extreme sea-level events for our higher GMSL projections relative to CMIP5.
240-253
Goodwin, Philip
87dbb154-5c39-473a-8121-c794487ee1fd
Haigh, Ivan
945ff20a-589c-47b7-b06f-61804367eb2d
Rohling, Eelco
a2a27ef2-fcce-4c71-907b-e692b5ecc685
Slangen, Aimee
ed3ed392-9b7d-4e0a-ab53-7e5486444998
Goodwin, Philip
87dbb154-5c39-473a-8121-c794487ee1fd
Haigh, Ivan
945ff20a-589c-47b7-b06f-61804367eb2d
Rohling, Eelco
a2a27ef2-fcce-4c71-907b-e692b5ecc685
Slangen, Aimee
ed3ed392-9b7d-4e0a-ab53-7e5486444998

Goodwin, Philip, Haigh, Ivan, Rohling, Eelco and Slangen, Aimee (2017) A new approach to projecting 21st century sea-level changes and extremes. Earth's Future, 5 (2), 240-253. (doi:10.1002/2016EF000508).

Record type: Article

Abstract

Future increases in flooding potential around the world’s coastlines from extreme sea level events is heavily dependent on projections of future Global Mean Sea Level (GMSL) rise. Yet the two main approaches for projecting 21st century GMSL rise – i.e., process-based versus semi-empirical – give inconsistent results. Here, a novel hybrid approach to GMSL projection, containing a process-based thermosteric contribution and a semi-empirical ice-melt contribution, is embedded within a conceptual Earth System Model (ESM). The ESM is run 10 million times with random perturbations to multiple parameters, and future projections are made only from the simulations that are historically consistent. The projections from our hybrid approach are found to be consistent with the dominant process-based GMSL projections from the Climate Model Intercomparison Project phase 5 (CMIP5) ensemble, in that our future ensemble-mean projections lie within ±2 cm of CMIP5 for the end of the 21st century when CMIP5 simulated histories are used to constrain our approach. However, when observations are used to provide the historic constraints for our hybrid approach, we find higher ice-melt sensitivity and additional ensemble-mean GMSL rise of around 13 to 16 cm by the end of the century. We assess the impact of this additional GMSL rise, projected from observation-consistency, on the increase in frequency of extreme sea level events for 220 coastal tide-gauge sites. Accounting for regional effects, we infer a 1.5 to 8 times increase in the frequency of extreme sea-level events for our higher GMSL projections relative to CMIP5.

Text
GHRS_EarthsFuture_Jan17_eprints.pdf - Accepted Manuscript
Download (592kB)
Text
Goodwin_et_al-2017-Earth's_Future - Version of Record
Available under License Creative Commons Attribution.
Download (1MB)

More information

Accepted/In Press date: 26 January 2017
e-pub ahead of print date: 24 February 2017
Published date: 24 February 2017
Additional Information: Funded by NERC: Mechanistic Controls of Surface Warming by Ocean Heat and Carbon Uptake (NE/N009789/1)
Organisations: Ocean and Earth Science, Physical Oceanography, Paleooceanography & Palaeoclimate

Identifiers

Local EPrints ID: 405182
URI: http://eprints.soton.ac.uk/id/eprint/405182
PURE UUID: 8a90406c-5765-4565-943e-5ea8b56e3e83
ORCID for Philip Goodwin: ORCID iD orcid.org/0000-0002-2575-8948
ORCID for Ivan Haigh: ORCID iD orcid.org/0000-0002-9722-3061
ORCID for Eelco Rohling: ORCID iD orcid.org/0000-0001-5349-2158

Catalogue record

Date deposited: 27 Jan 2017 11:49
Last modified: 01 Apr 2022 01:44

Export record

Altmetrics

Contributors

Author: Philip Goodwin ORCID iD
Author: Ivan Haigh ORCID iD
Author: Eelco Rohling ORCID iD
Author: Aimee Slangen

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×