Global glacier volume projections under high-end climate change scenarios
The Paris agreement aims to hold global warming to well below 2 ∘ C and to pursue efforts to limit it to 1.5 ∘ C relative to the pre-industrial period. Recent estimates based on population growth and intended carbon emissions from participant countries suggest global warming may exceed this ambitiou...
Published in: | The Cryosphere |
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Main Authors: | , , , , , , , , , |
Format: | Text |
Language: | English |
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2019
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Online Access: | https://doi.org/10.5194/tc-13-325-2019 https://tc.copernicus.org/articles/13/325/2019/ |
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Open Polar |
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Copernicus Publications: E-Journals |
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English |
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The Paris agreement aims to hold global warming to well below 2 ∘ C and to pursue efforts to limit it to 1.5 ∘ C relative to the pre-industrial period. Recent estimates based on population growth and intended carbon emissions from participant countries suggest global warming may exceed this ambitious target. Here we present glacier volume projections for the end of this century, under a range of high-end climate change scenarios, defined as exceeding +2 ∘ C global average warming relative to the pre-industrial period. Glacier volume is modelled by developing an elevation-dependent mass balance model for the Joint UK Land Environment Simulator (JULES). To do this, we modify JULES to include glaciated and unglaciated surfaces that can exist at multiple heights within a single grid box. Present-day mass balance is calibrated by tuning albedo, wind speed, precipitation, and temperature lapse rates to obtain the best agreement with observed mass balance profiles. JULES is forced with an ensemble of six Coupled Model Intercomparison Project Phase 5 (CMIP5) models, which were downscaled using the high-resolution HadGEM3-A atmosphere-only global climate model. The CMIP5 models use the RCP8.5 climate change scenario and were selected on the criteria of passing 2 ∘ C global average warming during this century. The ensemble mean volume loss at the end of the century plus or minus 1 standard deviation is <math xmlns="http://www.w3.org/1998/Math/MathML" id="M6" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">64</mn><mo>±</mo><mn mathvariant="normal">5</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="39pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="64498044f10293b5ab66b017e349e280"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-13-325-2019-ie00001.svg" width="39pt" height="10pt" src="tc-13-325-2019-ie00001.png"/></svg:svg> % for all glaciers excluding those on the peripheral of the Antarctic ice sheet. The uncertainty in the multi-model mean is rather small and caused by the sensitivity of HadGEM3-A to the boundary conditions supplied by the CMIP5 models. The regions which lose more than 75 % of their initial volume by the end of the century are Alaska, western Canada and the US, Iceland, Scandinavia, the Russian Arctic, central Europe, Caucasus, high-mountain Asia, low latitudes, southern Andes, and New Zealand. The ensemble mean ice loss expressed in sea level equivalent contribution is 215.2±21.3 mm. The largest contributors to sea level rise are Alaska ( 44.6±1.1 mm), Arctic Canada north and south ( 34.9±3.0 mm), the Russian Arctic ( 33.3±4.8 mm), Greenland ( 20.1±4.4 ), high-mountain Asia (combined central Asia, South Asia east and west), ( 18.0±0.8 mm), southern Andes ( 14.4±0.1 mm), and Svalbard ( 17.0±4.6 mm). Including parametric uncertainty in the calibrated mass balance parameters gives an upper bound global volume loss of 281.1 mm of sea level equivalent by the end of the century. Such large ice losses will have inevitable consequences for sea level rise and for water supply in glacier-fed river systems. |
format |
Text |
author |
Shannon, Sarah Smith, Robin Wiltshire, Andy Payne, Tony Huss, Matthias Betts, Richard Caesar, John Koutroulis, Aris Jones, Darren Harrison, Stephan |
spellingShingle |
Shannon, Sarah Smith, Robin Wiltshire, Andy Payne, Tony Huss, Matthias Betts, Richard Caesar, John Koutroulis, Aris Jones, Darren Harrison, Stephan Global glacier volume projections under high-end climate change scenarios |
author_facet |
Shannon, Sarah Smith, Robin Wiltshire, Andy Payne, Tony Huss, Matthias Betts, Richard Caesar, John Koutroulis, Aris Jones, Darren Harrison, Stephan |
author_sort |
Shannon, Sarah |
title |
Global glacier volume projections under high-end climate change scenarios |
title_short |
Global glacier volume projections under high-end climate change scenarios |
title_full |
Global glacier volume projections under high-end climate change scenarios |
title_fullStr |
Global glacier volume projections under high-end climate change scenarios |
title_full_unstemmed |
Global glacier volume projections under high-end climate change scenarios |
title_sort |
global glacier volume projections under high-end climate change scenarios |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-325-2019 https://tc.copernicus.org/articles/13/325/2019/ |
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ENVELOPE(140.917,140.917,-66.742,-66.742) |
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Antarctic Arctic Canada Greenland Jules New Zealand Svalbard The Antarctic |
geographic_facet |
Antarctic Arctic Canada Greenland Jules New Zealand Svalbard The Antarctic |
genre |
albedo Antarc* Antarctic Arctic Climate change glacier glacier glacier glacier glacier* glaciers Global warming Greenland Ice Sheet Iceland Svalbard Alaska |
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albedo Antarc* Antarctic Arctic Climate change glacier glacier glacier glacier glacier* glaciers Global warming Greenland Ice Sheet Iceland Svalbard Alaska |
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eISSN: 1994-0424 |
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doi:10.5194/tc-13-325-2019 https://tc.copernicus.org/articles/13/325/2019/ |
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https://doi.org/10.5194/tc-13-325-2019 |
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The Cryosphere |
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13 |
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1 |
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325 |
op_container_end_page |
350 |
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1766249765236899840 |
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ftcopernicus:oai:publications.copernicus.org:tc66728 2023-05-15T13:11:58+02:00 Global glacier volume projections under high-end climate change scenarios Shannon, Sarah Smith, Robin Wiltshire, Andy Payne, Tony Huss, Matthias Betts, Richard Caesar, John Koutroulis, Aris Jones, Darren Harrison, Stephan 2019-02-01 application/pdf https://doi.org/10.5194/tc-13-325-2019 https://tc.copernicus.org/articles/13/325/2019/ eng eng doi:10.5194/tc-13-325-2019 https://tc.copernicus.org/articles/13/325/2019/ eISSN: 1994-0424 Text 2019 ftcopernicus https://doi.org/10.5194/tc-13-325-2019 2020-07-20T16:22:57Z The Paris agreement aims to hold global warming to well below 2 ∘ C and to pursue efforts to limit it to 1.5 ∘ C relative to the pre-industrial period. Recent estimates based on population growth and intended carbon emissions from participant countries suggest global warming may exceed this ambitious target. Here we present glacier volume projections for the end of this century, under a range of high-end climate change scenarios, defined as exceeding +2 ∘ C global average warming relative to the pre-industrial period. Glacier volume is modelled by developing an elevation-dependent mass balance model for the Joint UK Land Environment Simulator (JULES). To do this, we modify JULES to include glaciated and unglaciated surfaces that can exist at multiple heights within a single grid box. Present-day mass balance is calibrated by tuning albedo, wind speed, precipitation, and temperature lapse rates to obtain the best agreement with observed mass balance profiles. JULES is forced with an ensemble of six Coupled Model Intercomparison Project Phase 5 (CMIP5) models, which were downscaled using the high-resolution HadGEM3-A atmosphere-only global climate model. The CMIP5 models use the RCP8.5 climate change scenario and were selected on the criteria of passing 2 ∘ C global average warming during this century. The ensemble mean volume loss at the end of the century plus or minus 1 standard deviation is <math xmlns="http://www.w3.org/1998/Math/MathML" id="M6" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">64</mn><mo>±</mo><mn mathvariant="normal">5</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="39pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="64498044f10293b5ab66b017e349e280"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-13-325-2019-ie00001.svg" width="39pt" height="10pt" src="tc-13-325-2019-ie00001.png"/></svg:svg> % for all glaciers excluding those on the peripheral of the Antarctic ice sheet. The uncertainty in the multi-model mean is rather small and caused by the sensitivity of HadGEM3-A to the boundary conditions supplied by the CMIP5 models. The regions which lose more than 75 % of their initial volume by the end of the century are Alaska, western Canada and the US, Iceland, Scandinavia, the Russian Arctic, central Europe, Caucasus, high-mountain Asia, low latitudes, southern Andes, and New Zealand. The ensemble mean ice loss expressed in sea level equivalent contribution is 215.2±21.3 mm. The largest contributors to sea level rise are Alaska ( 44.6±1.1 mm), Arctic Canada north and south ( 34.9±3.0 mm), the Russian Arctic ( 33.3±4.8 mm), Greenland ( 20.1±4.4 ), high-mountain Asia (combined central Asia, South Asia east and west), ( 18.0±0.8 mm), southern Andes ( 14.4±0.1 mm), and Svalbard ( 17.0±4.6 mm). Including parametric uncertainty in the calibrated mass balance parameters gives an upper bound global volume loss of 281.1 mm of sea level equivalent by the end of the century. Such large ice losses will have inevitable consequences for sea level rise and for water supply in glacier-fed river systems. Text albedo Antarc* Antarctic Arctic Climate change glacier glacier glacier glacier glacier* glaciers Global warming Greenland Ice Sheet Iceland Svalbard Alaska Copernicus Publications: E-Journals Antarctic Arctic Canada Greenland Jules ENVELOPE(140.917,140.917,-66.742,-66.742) New Zealand Svalbard The Antarctic The Cryosphere 13 1 325 350 |