Transition to a much warmer climate for the global ocean and Antarctic Ice Sheet coupled system, and its reversibility
- 1Université Grenoble Alpes (Saint-Martin-d'Hères, France)
Abstract
In Antarctica, two plausible tipping points have been suggested: an ocean tipping point involving a cold-to-warm transition of ice-shelf cavities, and an ice-sheet tipping point associated with the marine ice-sheet instability. This study explores the existence of such tipping points at the scale of Antarctica, using a coupled ocean–ice-sheet model. We first apply and then remove an abrupt perturbation to the ocean, instantaneously switching the atmospheric forcing to high-end 23rd century conditions, which shifts all ice-shelf cavities of Antarctica to warm conditions. With the assumption of fixed ice-shelf front positions, our simulations reveal that Antarctic continental shelf waters rapidly warm, leading to a regime shift with increased ice-shelf melt rates, significant ice-shelf thinning, and retreat of ice-sheet grounding lines. The ocean conditions reverse within 40 years when the atmospheric perturbation ceases, while the ice sheet’s response is much slower. Some regions of East Antarctica show signs of ice-sheet reversibility over several centuries. In contrast, we identify 14 ice streams, primarily in the Ross, Amundsen, Filchner, Ronne, and Dronning Maud Land basins, that still undergo irreversible retreat several centuries after the removal of the perturbation.
Versions
Related
- Life Cycle of Retrogressive Thaw Slumps in a Warmer and Wetter Climate on the Central Qinghai-Tibet Plateau
- On the Role of the Antarctic Slope Front on the Occurrence of the Weddell Sea Polynya under Climate Change
- Hybrid models generalize better to warmer climate conditions than process-based and purely data-driven models
- Fully coupled climate–ice-sheet ensemble indicates Greenland Ice Sheet contributed at least one quarter of Last Interglacial sea-level highstand
- What is the price of the climate transition planning ?
BibTeX
@article{mathiot2026transition,
title = {{Transition to a much warmer climate for the global ocean and Antarctic Ice Sheet coupled system, and its reversibility}},
author = {Pierre Mathiot and Nicolas C. Jourdain and Benoit Urruty and Fabien Gillet-Chaulet and Olivier Gagliardini and Gael Durand},
journal = {The Cryosphere},
year = {2026},
month = nov,
doi = {10.5194/tc-20-6241-2026},
url = {https://doi.org/10.5194/tc-20-6241-2026},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Transition to a much warmer climate for the global ocean and Antarctic Ice Sheet coupled system, and its reversibility
AU - Pierre Mathiot
AU - Nicolas C. Jourdain
AU - Benoit Urruty
AU - Fabien Gillet-Chaulet
AU - Olivier Gagliardini
AU - Gael Durand
PY - 2026
DA - 2026/11/02
JO - The Cryosphere
DO - 10.5194/tc-20-6241-2026
UR - https://doi.org/10.5194/tc-20-6241-2026
AB - In Antarctica, two plausible tipping points have been suggested: an ocean tipping point involving a cold-to-warm transition of ice-shelf cavities, and an ice-sheet tipping point associated with the marine ice-sheet instability. This study explores the existence of such tipping points at the scale of Antarctica, using a coupled ocean–ice-sheet model. We first apply and then remove an abrupt perturbation to the ocean, instantaneously switching the atmospheric forcing to high-end 23rd century conditions, which shifts all ice-shelf cavities of Antarctica to warm conditions. With the assumption of fixed ice-shelf front positions, our simulations reveal that Antarctic continental shelf waters rapidly warm, leading to a regime shift with increased ice-shelf melt rates, significant ice-shelf thinning, and retreat of ice-sheet grounding lines. The ocean conditions reverse within 40 years when the atmospheric perturbation ceases, while the ice sheet’s response is much slower. Some regions of East Antarctica show signs of ice-sheet reversibility over several centuries. In contrast, we identify 14 ice streams, primarily in the Ross, Amundsen, Filchner, Ronne, and Dronning Maud Land basins, that still undergo irreversible retreat several centuries after the removal of the perturbation.
SN - 1994-0424
ER -