Skip to content

Ice sheet contributions to future sea-level rise from structured expert judgment

Research output: Contribution to journalArticle

Original languageEnglish
Pages (from-to)11195-11200
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume166
Issue number23
DOIs
DateAccepted/In press - 8 Apr 2019
DatePublished (current) - 20 May 2019

Abstract

Despite considerable advances in process understanding, numerical modeling, and the observational record of ice sheet contributions to global mean sea-level rise (SLR) since the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change, severe limitations remain in the predictive capability of ice sheet models. As a consequence, the potential contributions of ice sheets remain the largest source of uncertainty in projecting future SLR. Here, we report the findings of a structured expert judgement study, using unique techniques for modeling correlations between inter- and intra-ice sheet processes and their tail dependences. We find that since the AR5, expert uncertainty has grown, in particular because of uncertain ice dynamic effects. For a +2 °C temperature scenario consistent with the Paris Agreement, we obtain a median estimate of a 26 cm SLR contribution by 2100, with a 95th percentile value of 81 cm. For a +5 °C temperature scenario more consistent with unchecked emissions growth, the corresponding values are 51 and 178 cm, respectively. Inclusion of thermal expansion and glacier contributions results in a global total SLR estimate that exceeds 2 m at the 95th percentile. Our findings support the use of scenarios of 21st century global total SLR exceeding 2 m for planning purposes. Beyond 2100, uncertainty and projected SLR increase rapidly. The 95th percentile ice sheet contribution by 2200, for the +5 °C scenario, is 7.5 m as a result of instabilities coming into play in both West and East Antarctica. Introducing process correlations and tail dependences increases estimates by roughly 15%.

    Research areas

  • Antarctica, Climate predictions, Greenland, Ice sheets, Sea-level rise

Documents

Documents

  • Full-text PDF (final published version)

    Rights statement: This is the final published version of the article (version of record). It first appeared online via PNAS at https://doi.org/10.1073/pnas.1817205116 . Please refer to any applicable terms of use of the publisher.

    Final published version, 793 KB, PDF-document

    Embargo ends: 20/11/19

    Request copy

    Licence: CC BY-NC-ND

DOI

View research connections

Related faculties, schools or groups