Cooling, vegetation shift and decline in monsoonal rainfall in NE Tibet through the greenhouse to icehouse transition
International audience Understanding how and why global climate tipped from greenhouse to icehouse conditions remains a major challenge.This critical shift is well documented in the marine realm characterized by a steady decline in global temperatureuntil a large and rapid cooling step at the Eocene...
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ftunivparis:oai:HAL:insu-02090855v1 2024-02-11T09:57:58+01:00 Cooling, vegetation shift and decline in monsoonal rainfall in NE Tibet through the greenhouse to icehouse transition Dupont-Nivet, Guillaume Page, Mara Meijer, Niels Barbolini, Natasha Al., Et Géosciences Rennes (GR) Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR) Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS) Key Laboratory of Orogenic Belts and Crustal Evolution Peking University Beijing Institute of Earth and Environmental Science Potsdam University of Potsdam = Universität Potsdam University of Washington Seattle Institut de Physique du Globe de Paris (IPGP) Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS) Vienne, Austria 2019-04-07 https://insu.hal.science/insu-02090855 en eng HAL CCSD insu-02090855 https://insu.hal.science/insu-02090855 European Geosciences Union General Assembly 2019 https://insu.hal.science/insu-02090855 European Geosciences Union General Assembly 2019, Apr 2019, Vienne, Austria. , 21, pp.EGU2019-15139, 2019, Geophysical Research Abstracts https://www.egu2019.eu/ [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology info:eu-repo/semantics/conferenceObject Conference poster 2019 ftunivparis 2024-01-24T17:28:26Z International audience Understanding how and why global climate tipped from greenhouse to icehouse conditions remains a major challenge.This critical shift is well documented in the marine realm characterized by a steady decline in global temperatureuntil a large and rapid cooling step at the Eocene-Oligocene Transition (EOT). However, the chronology andmechanisms of cooling on land remain unclear. To reconstruct Paleogene climate conditions for the Tibetan Plateauand the Asian continental interior, clumped isotope thermometry and palynology in accurately-dated continentalrecords from northeastern Tibet, are here combined with climate and vegetation simulations. Our results show twosuccessive dramatic (>9 C) drops in soil carbonate temperature, at 37 Ma and at 33.5 Ma associated respectivelywith the appearance and dominance of high altitude conifer forests. Such large temperature decreases associatedwith ecological reorganisations cannot result from regional cooling alone. They require shifting of the rainy seasonto cooler months, which we interpret to reflect a decline of monsoonal intensity. Our results suggest that theresponse of Asian temperatures, monsoonal rainfall and vegetation to the decline of atmospheric CO2 and globaltemperature through the late Eocene occurred in two steps separated by a period of climatic instability. Our resultssupport the onset of the Antarctic Circumpolar Current coeval to the Oligocene isotope event 1 (Oi-1) glaciationat 33.5 Ma, reshaping the distribution of surface heat worldwide; however, the origin of the 37 Ma cooling eventremains to be determined. Conference Object Antarc* Antarctic Université de Paris: Portail HAL Antarctic The Antarctic |
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Open Polar |
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Université de Paris: Portail HAL |
op_collection_id |
ftunivparis |
language |
English |
topic |
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
spellingShingle |
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology Dupont-Nivet, Guillaume Page, Mara Meijer, Niels Barbolini, Natasha Al., Et Cooling, vegetation shift and decline in monsoonal rainfall in NE Tibet through the greenhouse to icehouse transition |
topic_facet |
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
description |
International audience Understanding how and why global climate tipped from greenhouse to icehouse conditions remains a major challenge.This critical shift is well documented in the marine realm characterized by a steady decline in global temperatureuntil a large and rapid cooling step at the Eocene-Oligocene Transition (EOT). However, the chronology andmechanisms of cooling on land remain unclear. To reconstruct Paleogene climate conditions for the Tibetan Plateauand the Asian continental interior, clumped isotope thermometry and palynology in accurately-dated continentalrecords from northeastern Tibet, are here combined with climate and vegetation simulations. Our results show twosuccessive dramatic (>9 C) drops in soil carbonate temperature, at 37 Ma and at 33.5 Ma associated respectivelywith the appearance and dominance of high altitude conifer forests. Such large temperature decreases associatedwith ecological reorganisations cannot result from regional cooling alone. They require shifting of the rainy seasonto cooler months, which we interpret to reflect a decline of monsoonal intensity. Our results suggest that theresponse of Asian temperatures, monsoonal rainfall and vegetation to the decline of atmospheric CO2 and globaltemperature through the late Eocene occurred in two steps separated by a period of climatic instability. Our resultssupport the onset of the Antarctic Circumpolar Current coeval to the Oligocene isotope event 1 (Oi-1) glaciationat 33.5 Ma, reshaping the distribution of surface heat worldwide; however, the origin of the 37 Ma cooling eventremains to be determined. |
author2 |
Géosciences Rennes (GR) Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR) Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS) Key Laboratory of Orogenic Belts and Crustal Evolution Peking University Beijing Institute of Earth and Environmental Science Potsdam University of Potsdam = Universität Potsdam University of Washington Seattle Institut de Physique du Globe de Paris (IPGP) Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS) |
format |
Conference Object |
author |
Dupont-Nivet, Guillaume Page, Mara Meijer, Niels Barbolini, Natasha Al., Et |
author_facet |
Dupont-Nivet, Guillaume Page, Mara Meijer, Niels Barbolini, Natasha Al., Et |
author_sort |
Dupont-Nivet, Guillaume |
title |
Cooling, vegetation shift and decline in monsoonal rainfall in NE Tibet through the greenhouse to icehouse transition |
title_short |
Cooling, vegetation shift and decline in monsoonal rainfall in NE Tibet through the greenhouse to icehouse transition |
title_full |
Cooling, vegetation shift and decline in monsoonal rainfall in NE Tibet through the greenhouse to icehouse transition |
title_fullStr |
Cooling, vegetation shift and decline in monsoonal rainfall in NE Tibet through the greenhouse to icehouse transition |
title_full_unstemmed |
Cooling, vegetation shift and decline in monsoonal rainfall in NE Tibet through the greenhouse to icehouse transition |
title_sort |
cooling, vegetation shift and decline in monsoonal rainfall in ne tibet through the greenhouse to icehouse transition |
publisher |
HAL CCSD |
publishDate |
2019 |
url |
https://insu.hal.science/insu-02090855 |
op_coverage |
Vienne, Austria |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
European Geosciences Union General Assembly 2019 https://insu.hal.science/insu-02090855 European Geosciences Union General Assembly 2019, Apr 2019, Vienne, Austria. , 21, pp.EGU2019-15139, 2019, Geophysical Research Abstracts https://www.egu2019.eu/ |
op_relation |
insu-02090855 https://insu.hal.science/insu-02090855 |
_version_ |
1790593516454281216 |