Global mean sea level over the past 4.5 million years

Peter U. Clark; Jeremy D. Shakun; Yair Rosenthal; David Pollard; Steven W Hostetler; Peter Köhler; Patrick J. Bartlein; Jonathan M. Gregory; Chenyu Zhu; Daniel P. Schrag; Zhengyu Liu; Nicklas G. Pisias

doi:10.1126/science.adv8389

Global mean sea level over the past 4.5 million years

Peter U. Clark
, Jeremy D. Shakun
, Yair Rosenthal
, David Pollard
, Steven W Hostetler
, Peter Köhler
, Patrick J. Bartlein
, Jonathan M. Gregory
, Chenyu Zhu
, Daniel P. Schrag
, Zhengyu Liu
, Nicklas G. Pisias

Research output: Contribution to journal › Article › peer-review

28 Citations (Scopus)

52 Downloads (Pure)

Abstract

Changes in global mean sea level (GMSL) during the late Cenozoic remain uncertain. We use a reconstruction of changes in δ 18O of seawater to reconstruct GMSL since 4.5 million years ago (Ma) that accounts for temperature-driven changes in the δ 18O of global ice sheets. Between 4.5 and 3 Ma, sea level highstands remained up to 20 m above present whereas the first lowstands below present suggest onset of Northern Hemisphere glaciation at 4 Ma. Intensification of global glaciation occurred from 3 Ma to 2.5 Ma, culminating in lowstands similar to the Last Glacial Maximum lowstand at 21,000 years ago and that reoccurred throughout much of the Pleistocene. We attribute the middle Pleistocene transition in ice sheet variability (1.2 Ma to 0.62 Ma) to modulation of 41-thousand-year (kyr) obliquity forcing by an increase in ~100-kyr CO 2 variability.

Original language	English
Article number	eadv8389
Journal	Science
Volume	390
Issue number	6770
Early online date	16 Oct 2025
DOIs	https://doi.org/10.1126/science.adv8389
Publication status	Published (in print/issue) - 16 Oct 2025

Bibliographical note

Data Availability Statement

All data are available in the Supplementary Material.

Funding

This publication contributed to Beyond EPICA, a project of the European Union’s Horizon 2020 research and innovation program (Oldest Ice Core). This is Beyond EPICA publication number 45. This work was funded by the following: National Science Foundation OPP-2103032 (to P.U.C.); University of Oregon Fund for Faculty Excellence (to P.B.); National Science Foundation OCE-1810681 (to Z.L.); National Science Foundation OCE-1834208 (to Y.R.).

Funders	Funder number
National Science Foundation	OPP-2103032
University of Oregon	OCE-1810681, OCE-1834208

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 13 Climate Action
SDG 14 Life Below Water

Access to Document

10.1126/science.adv8389

Clark_Draft_SM_v2_no EndNote-AAMAuthor Accepted Manuscript, 10.1 MB

Cite this

@article{77003ad731d64d9090c739ad84749c41,

title = "Global mean sea level over the past 4.5 million years",

abstract = "Changes in global mean sea level (GMSL) during the late Cenozoic remain uncertain. We use a reconstruction of changes in δ 18O of seawater to reconstruct GMSL since 4.5 million years ago (Ma) that accounts for temperature-driven changes in the δ 18O of global ice sheets. Between 4.5 and 3 Ma, sea level highstands remained up to 20 m above present whereas the first lowstands below present suggest onset of Northern Hemisphere glaciation at 4 Ma. Intensification of global glaciation occurred from 3 Ma to 2.5 Ma, culminating in lowstands similar to the Last Glacial Maximum lowstand at 21,000 years ago and that reoccurred throughout much of the Pleistocene. We attribute the middle Pleistocene transition in ice sheet variability (1.2 Ma to 0.62 Ma) to modulation of 41-thousand-year (kyr) obliquity forcing by an increase in \textasciitilde{}100-kyr CO 2 variability. ",

author = "Clark, \{Peter U.\} and Shakun, \{Jeremy D.\} and Yair Rosenthal and David Pollard and Hostetler, \{Steven W\} and Peter K{\"o}hler and Bartlein, \{Patrick J.\} and Gregory, \{Jonathan M.\} and Chenyu Zhu and Schrag, \{Daniel P.\} and Zhengyu Liu and Pisias, \{Nicklas G.\}",

note = "Copyright {\textcopyright} 2025 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.",

year = "2025",

month = oct,

day = "16",

doi = "10.1126/science.adv8389",

language = "English",

volume = "390",

journal = "Science",

issn = "0036-8075",

publisher = "American Association for the Advancement of Science",

number = "6770",

}

TY - JOUR

T1 - Global mean sea level over the past 4.5 million years

AU - Clark, Peter U.

AU - Shakun, Jeremy D.

AU - Rosenthal, Yair

AU - Pollard, David

AU - Hostetler, Steven W

AU - Köhler, Peter

AU - Bartlein, Patrick J.

AU - Gregory, Jonathan M.

AU - Zhu, Chenyu

AU - Schrag, Daniel P.

AU - Liu, Zhengyu

AU - Pisias, Nicklas G.

PY - 2025/10/16

Y1 - 2025/10/16

N2 - Changes in global mean sea level (GMSL) during the late Cenozoic remain uncertain. We use a reconstruction of changes in δ 18O of seawater to reconstruct GMSL since 4.5 million years ago (Ma) that accounts for temperature-driven changes in the δ 18O of global ice sheets. Between 4.5 and 3 Ma, sea level highstands remained up to 20 m above present whereas the first lowstands below present suggest onset of Northern Hemisphere glaciation at 4 Ma. Intensification of global glaciation occurred from 3 Ma to 2.5 Ma, culminating in lowstands similar to the Last Glacial Maximum lowstand at 21,000 years ago and that reoccurred throughout much of the Pleistocene. We attribute the middle Pleistocene transition in ice sheet variability (1.2 Ma to 0.62 Ma) to modulation of 41-thousand-year (kyr) obliquity forcing by an increase in ~100-kyr CO 2 variability.

AB - Changes in global mean sea level (GMSL) during the late Cenozoic remain uncertain. We use a reconstruction of changes in δ 18O of seawater to reconstruct GMSL since 4.5 million years ago (Ma) that accounts for temperature-driven changes in the δ 18O of global ice sheets. Between 4.5 and 3 Ma, sea level highstands remained up to 20 m above present whereas the first lowstands below present suggest onset of Northern Hemisphere glaciation at 4 Ma. Intensification of global glaciation occurred from 3 Ma to 2.5 Ma, culminating in lowstands similar to the Last Glacial Maximum lowstand at 21,000 years ago and that reoccurred throughout much of the Pleistocene. We attribute the middle Pleistocene transition in ice sheet variability (1.2 Ma to 0.62 Ma) to modulation of 41-thousand-year (kyr) obliquity forcing by an increase in ~100-kyr CO 2 variability.

UR - https://www.scopus.com/pages/publications/105019114750

U2 - 10.1126/science.adv8389

DO - 10.1126/science.adv8389

M3 - Article

C2 - 41100616

SN - 0036-8075

VL - 390

JO - Science

JF - Science

IS - 6770

M1 - eadv8389

ER -

Global mean sea level over the past 4.5 million years

Abstract

Bibliographical note

Data Availability Statement

Funding

UN SDGs

Access to Document

Other files and links

Fingerprint

Cite this