Committed retreat: controls on glacier disequilibrium in a warming climate
ABSTRACT The widespread retreat of mountain glaciers is a striking emblem of recent climate change. Yet mass-balance observations indicate that many glaciers are out of equilibrium with current climate, meaning that observed retreats do not show the full response to warming. This is a fundamental co...
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Online Access: | http://dx.doi.org/10.1017/jog.2018.57 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143018000576 |
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crcambridgeupr:10.1017/jog.2018.57 2024-03-03T08:46:07+00:00 Committed retreat: controls on glacier disequilibrium in a warming climate CHRISTIAN, JOHN ERICH KOUTNIK, MICHELLE ROE, GERARD 2018 http://dx.doi.org/10.1017/jog.2018.57 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143018000576 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of Glaciology volume 64, issue 246, page 675-688 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 2018 crcambridgeupr https://doi.org/10.1017/jog.2018.57 2024-02-08T08:49:23Z ABSTRACT The widespread retreat of mountain glaciers is a striking emblem of recent climate change. Yet mass-balance observations indicate that many glaciers are out of equilibrium with current climate, meaning that observed retreats do not show the full response to warming. This is a fundamental consequence of glacier dynamics: mountain glaciers typically have multidecadal response timescales, and so their response lags centennial-scale climate trends. A substantial difference between transient and equilibrium glacier length persists throughout the warming period; we refer to this length difference as ‘disequilibrium’. Forcing idealized glacier geometries with gradual warming shows that the glacier response timescale fundamentally governs the evolution of disequilibrium. Comparing a hierarchy of different glacier models suggests that accurate estimates of ice thickness and climatology, which control the timescale, are more important than higher order ice dynamics for capturing disequilibrium. Current glacier disequilibrium has previously been estimated for a selection of individual glaciers; our idealized modeling shows that sustained disequilibrium is a fundamental response of glacier dynamics, and is robust across a range of glacier geometries. This implies that many mountain glaciers are committed to additional, kilometer-scale retreats, even without further warming. Disequilibrium must also be addressed when calibrating glacier models used for climate reconstructions and projections of retreat in response to future warming. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 64 246 675 688 |
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Cambridge University Press |
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English |
topic |
Earth-Surface Processes |
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Earth-Surface Processes CHRISTIAN, JOHN ERICH KOUTNIK, MICHELLE ROE, GERARD Committed retreat: controls on glacier disequilibrium in a warming climate |
topic_facet |
Earth-Surface Processes |
description |
ABSTRACT The widespread retreat of mountain glaciers is a striking emblem of recent climate change. Yet mass-balance observations indicate that many glaciers are out of equilibrium with current climate, meaning that observed retreats do not show the full response to warming. This is a fundamental consequence of glacier dynamics: mountain glaciers typically have multidecadal response timescales, and so their response lags centennial-scale climate trends. A substantial difference between transient and equilibrium glacier length persists throughout the warming period; we refer to this length difference as ‘disequilibrium’. Forcing idealized glacier geometries with gradual warming shows that the glacier response timescale fundamentally governs the evolution of disequilibrium. Comparing a hierarchy of different glacier models suggests that accurate estimates of ice thickness and climatology, which control the timescale, are more important than higher order ice dynamics for capturing disequilibrium. Current glacier disequilibrium has previously been estimated for a selection of individual glaciers; our idealized modeling shows that sustained disequilibrium is a fundamental response of glacier dynamics, and is robust across a range of glacier geometries. This implies that many mountain glaciers are committed to additional, kilometer-scale retreats, even without further warming. Disequilibrium must also be addressed when calibrating glacier models used for climate reconstructions and projections of retreat in response to future warming. |
format |
Article in Journal/Newspaper |
author |
CHRISTIAN, JOHN ERICH KOUTNIK, MICHELLE ROE, GERARD |
author_facet |
CHRISTIAN, JOHN ERICH KOUTNIK, MICHELLE ROE, GERARD |
author_sort |
CHRISTIAN, JOHN ERICH |
title |
Committed retreat: controls on glacier disequilibrium in a warming climate |
title_short |
Committed retreat: controls on glacier disequilibrium in a warming climate |
title_full |
Committed retreat: controls on glacier disequilibrium in a warming climate |
title_fullStr |
Committed retreat: controls on glacier disequilibrium in a warming climate |
title_full_unstemmed |
Committed retreat: controls on glacier disequilibrium in a warming climate |
title_sort |
committed retreat: controls on glacier disequilibrium in a warming climate |
publisher |
Cambridge University Press (CUP) |
publishDate |
2018 |
url |
http://dx.doi.org/10.1017/jog.2018.57 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143018000576 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 64, issue 246, page 675-688 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2018.57 |
container_title |
Journal of Glaciology |
container_volume |
64 |
container_issue |
246 |
container_start_page |
675 |
op_container_end_page |
688 |
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1792502045675094016 |