E.J. Rohling et al., Nature Geosci., 2009, Antarctic temperature and global sea level closely coupled over the past five glacial cycles

Nature Geoscience, published online 21 June 2009; doi:10.1038/ngeo557

Antarctic temperature and global sea level closely coupled over the past five glacial cycles

E. J. Rohling¹, K. Grant¹, M. Bolshaw¹, A. P. Roberts¹, M. Siddall^2,4, Ch. Hemleben³ and M. Kucera³

Abstract

Ice cores from Antarctica record temperature and atmospheric carbon dioxide variations over the past six glacial cycles^{1, 2}. Yet concomitant records of sea-level fluctuations (needed to reveal rates and magnitudes of ice-volume change that provide context to projections for the future^{3, 4, 5, 6, 7, 8, 9}) remain elusive. Reconstructions indicate fast rates of sea-level rise up to 5 cm/yr during glacial terminations¹⁰, and 1–2 cm/yr during interglacials^{11, 12} and within the past glacial cycle¹³. However, little is known about the total long-term sea-level rise in equilibration to warming. Here we present a sea-level record for the past 520,000 years based on stable oxygen isotope analyses of planktonic foraminifera and bulk sediments from the Red Sea. Our record reveals a strong correlation on multi-millennial timescales between global sea level and Antarctic temperature¹, which is related to global temperature^{6, 7}. On the basis of this correlation, we estimate sea level for the Middle Pliocene epoch (3.0–3.5 Myr ago)—a period with near-modern CO₂ levels—at 255 m above present, which is validated by independent sea-level data^{6, 14, 15, 16}. Our results imply that even stabilization at today's CO₂ levels may cause sea-level rise over several millennia that by far exceeds existing long-term projections³.

1. School of Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton SO14 3ZH, U.K.
2. Lamont-Doherty Earth Observatory, 61 Route 9W, P. O. Box 1000, Palisades, NY 10964-8000, U.S.A.
3. Institute of Geosciences, University of Tübingen, Sigwartstrasse 10, 72076, Tübingen, Germany
4. Present address: Department of Earth Science, University of Bristol, Will's Memorial Building, Queen's Road, Bristol BS8 1RJ, U.K.

*Correspondence, e-mail: E.Rohling@noc.soton.ac.uk

Link to abstract: http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo557.html