OS026-04
Changing State of Earth’s Climate for the last 66 Million Years
Thursday, 10 December 2020: 05:42
Virtual
Thomas Westerhold1, Norbert Marwan2,3, Anna Joy Drury1,4, Diederik Liebrand1, Claudia Agnini5, Eleni Anagnostou6, James Barnet7,8, Steven M Bohaty9, David De Vleeschouwer1, Fabio Florindo10, Thomas Frederichs1,11, David A Hodell12, Ann Holbourn13, Dick Kroon14, Vittoria Lauretano15, Kate Littler16, Lucas Joost Lourens17, Mitchell W Lyle18, Heiko Paelike1, Ursula Roehl1, Jun Tian19, Roy Wilkens20, Paul A Wilson9 and James C Zachos21, (1)MARUM - University of Bremen, Bremen, Germany, (2)Potsdam Institute for Climate Impact Research, Potsdam, Germany, (3)University of Potsdam, Potsdam, Germany, (4)University College London, Department of Earth Sciences, London, United Kingdom, (5)University of Padua, Padua, Italy, (6)GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany, (7)University of Exeter, Camborne School of Mines, Exeter, United Kingdom, (8)School of Earth and Environmental Sciences, University of St Andrews, St Andrews, Scotland, UK, St Andrews, United Kingdom, (9)National Oceanography Centre, Southampton, United Kingdom, (10)INGV National Institute of Geophysics and Volcanology, Rome, Italy, (11)University of Bremen, Department of Geosciences, Bremen, Germany, (12)University of Cambridge, Godwin Laboratory for Palaeoclimate Research, Cambridge, United Kingdom, (13)Christian-Albrechts-University, Institute of Geosciences, Kiel, Germany, (14)University of Edinburgh, Edinburgh, United Kingdom, (15)University of Bristol, Department of Earth Sciences & Department of Chemistry, Bristol, United Kingdom, (16)University of Exeter, Camborne School of Mines, Penryn, United Kingdom, (17)Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Budapestlaan 4, 3584 CD, Utrecht, Netherlands, (18)Oregon State University, College of Earth Ocean and Atmospheric Science, Corvallis, OR, United States, (19)State Key Laboratory of Marine Geology, Tongji University, Shanghai, China, (20)University of Hawaii at Manoa, School of Ocean and Earth Science and Technology (SOEST), Honolulu, HI, United States, (21)University of California Santa Cruz, Santa Cruz, CA, United States
Abstract:
We combined the best available high-resolution ocean drilling records with newly generated data to produce a continuous, astronomically tuned 66-million-year record of global climate that can serve as a new Cenozoic global reference benthic foraminiferal carbon and oxygen isotope dataset (CENOGRID). The CENOGRID represents the first community effort to systematically assemble a high-fidelity deep-sea isotope record that captures the high and low frequency variations of the climate system on a global scale, providing the framework required for understanding the nature of the major climate states, transitions and events. Within the constraints imposed by temporal resolution in older segments and potential artefacts related to differences in the regional response to orbital forcing, (e.g., obliquity), this singly unique record reveals how long-term gradual shifts in boundary conditions, principally paleogeography, ice-volume, and the mean level of greenhouse gases create state dependent shifts in the sensitivity of the climate system to periodic oscillations in solar forcing. We believe that this phenomenon is related to feedbacks associated with the carbon cycle supporting the critical role of GHG in enhancing climate sensitivity to solar radiative forcing.
