1
|
Clark PU, Shakun JD, Rosenthal Y, Köhler P, Bartlein PJ. Global and regional temperature change over the past 4.5 million years. Science 2024; 383:884-890. [PMID: 38386742 DOI: 10.1126/science.adi1908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 01/16/2024] [Indexed: 02/24/2024]
Abstract
Much of our understanding of Cenozoic climate is based on the record of δ18O measured in benthic foraminifera. However, this measurement reflects a combined signal of global temperature and sea level, thus preventing a clear understanding of the interactions and feedbacks of the climate system in causing global temperature change. Our new reconstruction of temperature change over the past 4.5 million years includes two phases of long-term cooling, with the second phase of accelerated cooling during the Middle Pleistocene Transition (1.5 to 0.9 million years ago) being accompanied by a transition from dominant 41,000-year low-amplitude periodicity to dominant 100,000-year high-amplitude periodicity. Changes in the rates of long-term cooling and variability are consistent with changes in the carbon cycle driven initially by geologic processes, followed by additional changes in the Southern Ocean carbon cycle.
Collapse
Affiliation(s)
- Peter U Clark
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA
- School of Geography and Environmental Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK
| | - Jeremy D Shakun
- Department of Earth and Environmental Sciences, Boston College, Chestnut Hill, MA 02467, USA
| | - Yair Rosenthal
- Department of Marine and Coastal Science, Rutgers The State University, New Brunswick, NJ 08901, USA
- Department of Earth and Planetary Sciences, Rutgers The State University, New Brunswick, NJ 08901, USA
| | - Peter Köhler
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, 27570 Bremerhaven, Germany
| | | |
Collapse
|
2
|
Pöppelmeier F, Jeltsch-Thömmes A, Lippold J, Joos F, Stocker TF. Multi-proxy constraints on Atlantic circulation dynamics since the last ice age. NATURE GEOSCIENCE 2023; 16:349-356. [PMID: 37064010 PMCID: PMC10089918 DOI: 10.1038/s41561-023-01140-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 01/27/2023] [Indexed: 06/19/2023]
Abstract
Uncertainties persist in the understanding of the Atlantic meridional overturning circulation and its response to external perturbations such as freshwater or radiative forcing. Abrupt reduction of the Atlantic circulation is considered a climate tipping point that may have been crossed when Earth's climate was propelled out of the last ice age. However, the evolution of the circulation since the Last Glacial Maximum (22-18 thousand years ago) remains insufficiently constrained due to model and proxy limitations. Here we leverage information from both a compilation of proxy records that track various aspects of the circulation and climate model simulations to constrain the Atlantic circulation over the past 20,000 years. We find a coherent picture of a shallow and weak Atlantic overturning circulation during the Last Glacial Maximum that reconciles apparently conflicting proxy evidence. Model-data comparison of the last deglaciation-starting from this new, multiple constrained glacial state-indicates a muted response during Heinrich Stadial 1 and that water mass geometry did not fully adjust to the strong reduction in overturning circulation during the comparably short Younger Dryas period. This demonstrates that the relationship between freshwater forcing and Atlantic overturning strength is strongly dependent on the climatic and oceanic background state.
Collapse
Affiliation(s)
- Frerk Pöppelmeier
- Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Aurich Jeltsch-Thömmes
- Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Jörg Lippold
- Institute of Earth Sciences, Heidelberg University, Heidelberg, Germany
| | - Fortunat Joos
- Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Thomas F Stocker
- Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland
- Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| |
Collapse
|
3
|
Subglacial precipitates record Antarctic ice sheet response to late Pleistocene millennial climate cycles. Nat Commun 2022; 13:5428. [PMID: 36109505 PMCID: PMC9477832 DOI: 10.1038/s41467-022-33009-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 08/26/2022] [Indexed: 11/17/2022] Open
Abstract
Ice cores and offshore sedimentary records demonstrate enhanced ice loss along Antarctic coastal margins during millennial-scale warm intervals within the last glacial termination. However, the distal location and short temporal coverage of these records leads to uncertainty in both the spatial footprint of ice loss, and whether millennial-scale ice response occurs outside of glacial terminations. Here we present a >100kyr archive of periodic transitions in subglacial precipitate mineralogy that are synchronous with Late Pleistocene millennial-scale climate cycles. Geochemical and geochronologic data provide evidence for opal formation during cold periods via cryoconcentration of subglacial brine, and calcite formation during warm periods through the addition of subglacial meltwater originating from the ice sheet interior. These freeze-flush cycles represent cyclic changes in subglacial hydrologic-connectivity driven by ice sheet velocity fluctuations. Our findings imply that oscillating Southern Ocean temperatures drive a dynamic response in the Antarctic ice sheet on millennial timescales, regardless of the background climate state. Piccione et al find evidence for Antarctic ice sheet instability driven by millennial cycles in Southern Ocean temperature, providing clues for the mechanisms that link climate change and rapid Antarctic ice loss events.
Collapse
|
4
|
Rapid northern hemisphere ice sheet melting during the penultimate deglaciation. Nat Commun 2022; 13:3819. [PMID: 35780147 PMCID: PMC9250507 DOI: 10.1038/s41467-022-31619-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 06/27/2022] [Indexed: 11/17/2022] Open
Abstract
The rate and consequences of future high latitude ice sheet retreat remain a major concern given ongoing anthropogenic warming. Here, new precisely dated stalagmite data from NW Iberia provide the first direct, high-resolution records of periods of rapid melting of Northern Hemisphere ice sheets during the penultimate deglaciation. These records reveal the penultimate deglaciation initiated with rapid century-scale meltwater pulses which subsequently trigger abrupt coolings of air temperature in NW Iberia consistent with freshwater-induced AMOC slowdowns. The first of these AMOC slowdowns, 600-year duration, was shorter than Heinrich 1 of the last deglaciation. Although similar insolation forcing initiated the last two deglaciations, the more rapid and sustained rate of freshening in the eastern North Atlantic penultimate deglaciation likely reflects a larger volume of ice stored in the marine-based Eurasian Ice sheet during the penultimate glacial in contrast to the land-based ice sheet on North America as during the last glacial. Stalagmites from NW Iberia record the rapid demise of large ice sheets during the penultimate deglaciation, and reveal decadal-scale feedbacks between warming and ice melting.
Collapse
|
5
|
Barker S, Starr A, van der Lubbe J, Doughty A, Knorr G, Conn S, Lordsmith S, Owen L, Nederbragt A, Hemming S, Hall I, Levay L, Berke MA, Brentegani L, Caley T, Cartagena-Sierra A, Charles CD, Coenen JJ, Crespin JG, Franzese AM, Gruetzner J, Han X, Hines SKV, Jimenez Espejo FJ, Just J, Koutsodendris A, Kubota K, Lathika N, Norris RD, Periera Dos Santos T, Robinson R, Rolison JM, Simon MH, Tangunan D, Yamane M, Zhang H. Persistent influence of precession on northern ice sheet variability since the early Pleistocene. Science 2022; 376:961-967. [PMID: 35617392 DOI: 10.1126/science.abm4033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Prior to ~1 million years ago (Ma), variations in global ice volume were dominated by changes in obliquity; however, the role of precession remains unresolved. Using a record of North Atlantic ice rafting spanning the past 1.7 million years, we find that the onset of ice rafting within a given glacial cycle (reflecting ice sheet expansion) consistently occurred during times of decreasing obliquity whereas mass ice wasting (ablation) events were consistently tied to minima in precession. Furthermore, our results suggest that the ubiquitous association between precession-driven mass wasting events and glacial termination is a distinct feature of the mid to late Pleistocene. Before then (increasing), obliquity alone was sufficient to end a glacial cycle, before losing its dominant grip on deglaciation with the southward extension of Northern Hemisphere ice sheets since ~1 Ma.
Collapse
Affiliation(s)
- Stephen Barker
- School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK
| | - Aidan Starr
- School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK
| | - Jeroen van der Lubbe
- Department of Earth Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Alice Doughty
- School of Earth and Climate Sciences, University of Maine, Orono, ME, USA
| | | | - Stephen Conn
- School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK
| | - Sian Lordsmith
- School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK
| | - Lindsey Owen
- School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK
| | | | - Sidney Hemming
- Lamont-Doherty Earth Observatory, Columbia University, New York, NY, USA
| | - Ian Hall
- School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK
| | - Leah Levay
- International Ocean Discovery Program, Texas A&M University, College Station, TX, USA
| | | | - M A Berke
- Department of Civil Engineering & Geological Sciences, University of Notre Dame, USA
| | - L Brentegani
- Earth and Environmental Sciences, University of Technology Queensland, Australia
| | - T Caley
- EPOC, UMR CNRS 5805, University of Bordeaux, France
| | - A Cartagena-Sierra
- Department of Civil Engineering & Geological Sciences, University of Notre Dame, USA
| | - C D Charles
- Scripps Institution of Oceanography, University of California, USA
| | - J J Coenen
- Department of Geology, Northern Illinois University, USA
| | - J G Crespin
- EPOC, UMR CNRS 5805, University of Bordeaux, France
| | - A M Franzese
- School of Earth and Environmental Sciences, Hostos Community College (CUNY), USA
| | - J Gruetzner
- Geosciences, Alfred-Wegener-Institut for Polar and Marine Research, Germany
| | - X Han
- Second Institute of Oceanography, Key Laboratory of Submarine Science, China
| | - S K V Hines
- Woods Hole Oceanographic Institution, Woods Hole, USA
| | - F J Jimenez Espejo
- Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Japan
| | - J Just
- Geologisches Institut, Universität Kõln, Germany
| | - A Koutsodendris
- Institute of Earth Sciences, University of Heidelberg, Germany
| | - K Kubota
- Research Institute for Marine Geodynamics, Japan Agency for Marine-Earth Science and Technology, Japan
| | - N Lathika
- National Centre for Polar and Ocean Research, Ministry of Earth Sciences, Goa, India
| | - R D Norris
- Scripps Institution of Oceanography, University of California, USA
| | | | - R Robinson
- Graduate School of Oceanography, University of Rhode Island, USA
| | | | | | - D Tangunan
- School of Earth and Environmental Sciences, Cardiff University, UK
| | - M Yamane
- Institute for Space-Earth Environmental Research, Nagoya University, Japan
| | - H Zhang
- School of Ecology and Environmental Science, Yunnan University, China
| |
Collapse
|