The role of CO2 decline for the onset of Northern Hemisphere glaciation
The Pliocene–Pleistocene Transition (PPT), from around 3.2 to 2.5 million years ago (Ma), represented a major shift in the climate system and was characterized by a gradual cooling trend and the appearance of large continental ice sheets over northern Eurasia and North America. Paleo evidence indica...
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ftleibnizopen:oai:oai.leibnizopen.de:Ahc_iIcBdbrxVwz6BJ8f 2023-06-06T11:54:29+02:00 The role of CO2 decline for the onset of Northern Hemisphere glaciation Willeit, Matteo Ganopolski, Andrey Calov, Reinhard Robinson, Alexander Maslin, Mark 2015 application/pdf https://oa.tib.eu/renate/handle/123456789/9990 https://doi.org/10.34657/9028 eng eng Amsterdam [u.a.] : Elsevier CC BY 4.0 Unported https://creativecommons.org/licenses/by/4.0/ Quaternary science reviews : the international multidisciplinary research and review journal 119 (2015) Carbon dioxide Earth system modelling Ice sheets Northern hemishpere glaciation Paleoclimatology Pliocene-Pleistocene transition 550 article Text 2015 ftleibnizopen https://doi.org/10.34657/9028 2023-04-16T23:33:25Z The Pliocene–Pleistocene Transition (PPT), from around 3.2 to 2.5 million years ago (Ma), represented a major shift in the climate system and was characterized by a gradual cooling trend and the appearance of large continental ice sheets over northern Eurasia and North America. Paleo evidence indicates that the PPT was accompanied and possibly caused by a decrease in atmospheric CO2, but the temporal resolution of CO2 reconstructions is low for this period of time and uncertainties remain large. Therefore, instead of applying existent CO2 reconstructions we solved an ‘inverse’ problem by finding a schematic CO2 concentration scenario that allows us to simulate the temporal evolution of key climate characteristics in agreement with paleoclimate records. To this end, we performed an ensemble of transient simulations with an Earth system model of intermediate complexity from which we derived a best guess transient CO2 scenario for the interval from 3.2 to 2.4 Ma that gives the best fit between the simulated and reconstructed benthic δ18O and global sea surface temperature evolution. Our data-constrained CO2 scenarios are consistent with recent CO2 reconstructions and suggest a gradual CO2 decline from 375–425 to 275–300 ppm, between 3.2 and 2.4 Ma. In addition to a gradual decline, the best fit to paleoclimate data requires the existence of pronounced CO2 variability coherent with the 41-kyr (1 kyr = 1000 years) obliquity cycle. In our simulations the long-term CO2 decline is accompanied by a relatively abrupt intensification of Northern Hemisphere glaciation at around 2.7 Ma. This is the result of a threshold behaviour of the ice sheets response to gradual CO2 decrease and orbital forcing. The simulated Northern Hemisphere ice sheets during the early Pleistocene glacial cycles reach a maximum volume equivalent to a sea level drop of about 40 m. Both ice volume and benthic δ18O are dominated by 41-kyr cyclicity. Our simulations suggest that before 2.7 Ma Greenland was ice free during summer insolation maxima and ... Article in Journal/Newspaper Greenland LeibnizOpen (The Leibniz Association) Greenland |
institution |
Open Polar |
collection |
LeibnizOpen (The Leibniz Association) |
op_collection_id |
ftleibnizopen |
language |
English |
topic |
Carbon dioxide Earth system modelling Ice sheets Northern hemishpere glaciation Paleoclimatology Pliocene-Pleistocene transition 550 |
spellingShingle |
Carbon dioxide Earth system modelling Ice sheets Northern hemishpere glaciation Paleoclimatology Pliocene-Pleistocene transition 550 Willeit, Matteo Ganopolski, Andrey Calov, Reinhard Robinson, Alexander Maslin, Mark The role of CO2 decline for the onset of Northern Hemisphere glaciation |
topic_facet |
Carbon dioxide Earth system modelling Ice sheets Northern hemishpere glaciation Paleoclimatology Pliocene-Pleistocene transition 550 |
description |
The Pliocene–Pleistocene Transition (PPT), from around 3.2 to 2.5 million years ago (Ma), represented a major shift in the climate system and was characterized by a gradual cooling trend and the appearance of large continental ice sheets over northern Eurasia and North America. Paleo evidence indicates that the PPT was accompanied and possibly caused by a decrease in atmospheric CO2, but the temporal resolution of CO2 reconstructions is low for this period of time and uncertainties remain large. Therefore, instead of applying existent CO2 reconstructions we solved an ‘inverse’ problem by finding a schematic CO2 concentration scenario that allows us to simulate the temporal evolution of key climate characteristics in agreement with paleoclimate records. To this end, we performed an ensemble of transient simulations with an Earth system model of intermediate complexity from which we derived a best guess transient CO2 scenario for the interval from 3.2 to 2.4 Ma that gives the best fit between the simulated and reconstructed benthic δ18O and global sea surface temperature evolution. Our data-constrained CO2 scenarios are consistent with recent CO2 reconstructions and suggest a gradual CO2 decline from 375–425 to 275–300 ppm, between 3.2 and 2.4 Ma. In addition to a gradual decline, the best fit to paleoclimate data requires the existence of pronounced CO2 variability coherent with the 41-kyr (1 kyr = 1000 years) obliquity cycle. In our simulations the long-term CO2 decline is accompanied by a relatively abrupt intensification of Northern Hemisphere glaciation at around 2.7 Ma. This is the result of a threshold behaviour of the ice sheets response to gradual CO2 decrease and orbital forcing. The simulated Northern Hemisphere ice sheets during the early Pleistocene glacial cycles reach a maximum volume equivalent to a sea level drop of about 40 m. Both ice volume and benthic δ18O are dominated by 41-kyr cyclicity. Our simulations suggest that before 2.7 Ma Greenland was ice free during summer insolation maxima and ... |
format |
Article in Journal/Newspaper |
author |
Willeit, Matteo Ganopolski, Andrey Calov, Reinhard Robinson, Alexander Maslin, Mark |
author_facet |
Willeit, Matteo Ganopolski, Andrey Calov, Reinhard Robinson, Alexander Maslin, Mark |
author_sort |
Willeit, Matteo |
title |
The role of CO2 decline for the onset of Northern Hemisphere glaciation |
title_short |
The role of CO2 decline for the onset of Northern Hemisphere glaciation |
title_full |
The role of CO2 decline for the onset of Northern Hemisphere glaciation |
title_fullStr |
The role of CO2 decline for the onset of Northern Hemisphere glaciation |
title_full_unstemmed |
The role of CO2 decline for the onset of Northern Hemisphere glaciation |
title_sort |
role of co2 decline for the onset of northern hemisphere glaciation |
publisher |
Amsterdam [u.a.] : Elsevier |
publishDate |
2015 |
url |
https://oa.tib.eu/renate/handle/123456789/9990 https://doi.org/10.34657/9028 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Quaternary science reviews : the international multidisciplinary research and review journal 119 (2015) |
op_rights |
CC BY 4.0 Unported https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.34657/9028 |
_version_ |
1767960961298202624 |