Antarctic ice sheet - climate feedbacks under high future carbon emissions
Freshwater forcing from a retreating Antarctic Ice Sheet could have a wide range of impacts on future global climate. Here, we report on multi-century (present-2250) climate simulations performed using a fully coupled numerical model integrated under future greenhouse gas emissions scenarios IPCC RC...
| Main Authors: | , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
arXiv
2020
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.48550/arxiv.2005.09731 https://arxiv.org/abs/2005.09731 |
| Summary: | Freshwater forcing from a retreating Antarctic Ice Sheet could have a wide range of impacts on future global climate. Here, we report on multi-century (present-2250) climate simulations performed using a fully coupled numerical model integrated under future greenhouse gas emissions scenarios IPCC RCP4.5 and 8.5, with meltwater discharge provided by a dynamic-thermodynamic ice sheet model. Accounting for Antarctica's meltwater contribution raises sub-surface ocean temperatures by 1 C at the ice margin, beyond rates currently projected. In contrast, 2-10 C cooler surface air and ocean temperatures in the Southern Ocean cause sea ice to expand and delay the increase of projected global mean anthropogenic warming. In addition, the projected loss of Arctic winter sea ice and weakening of the Atlantic Meridional Overturning Circulation are delayed be several decades. Our results demonstrate a clear need to more accurately account for meltwater input from ice sheets if we are to make confident climate predictions. : 30 pages, 14 figures, submitted to Science Advances August 2019. This version is the original submission and does not reflect edits based on reviews. This work was also partially presented at AGU Fall Meeting in 2017 and 2018, AMS AOFD 2019, GCC 2019, AMS Annual 2020, AAG 2020 |
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