Recent climate and ice-sheet changes in West Antarctica compared with the past 2,000 years

Journal name:
Nature Geoscience
Year published:
Published online

Changes in atmospheric circulation over the past five decades have enhanced the wind-driven inflow of warm ocean water onto the Antarctic continental shelf, where it melts ice shelves from below1, 2, 3. Atmospheric circulation changes have also caused rapid warming4 over the West Antarctic Ice Sheet, and contributed to declining sea-ice cover in the adjacent Amundsen–Bellingshausen seas5. It is unknown whether these changes are part of a longer-term trend. Here, we use water-isotope (δ18O) data from an array of ice-core records to place recent West Antarctic climate changes in the context of the past two millennia. We find that the δ18O of West Antarctic precipitation has increased significantly in the past 50 years, in parallel with the trend in temperature, and was probably more elevated during the 1990s than at any other time during the past 200 years. However, δ18O anomalies comparable to those of recent decades occur about 1% of the time over the past 2,000 years. General circulation model simulations suggest that recent trends in δ18O and climate in West Antarctica cannot be distinguished from decadal variability that originates in the tropics. We conclude that the uncertain trajectory of tropical climate variability represents a significant source of uncertainty in projections of West Antarctic climate and ice-sheet change.

At a glance


  1. Map of West Antarctica.
    Figure 1: Map of West Antarctica.

    Ice-core locations are shown by filled circles. Blue shading shows the main Siple Coast and Amundsen Sea ice streams. Ice shelves are shaded grey. The inset map shows the locations of well-dated, annually resolved ice cores for which there are δ18O data available to at least 1994. WD, WAIS Divide ice core (white-edged circle). PIG, Pine Island Glacier. The location of the Byrd weather station is shown by an open circle.

  2. West Antarctic temperature and
    Figure 2: West Antarctic temperature and δ18O.

    a, Temperature 7 at Byrd Station (80°S, 120°W) (upper) and composite of annual mean δ18O anomalies from ice cores in West Antarctica (lower). The two time series are correlated at r=0.48, p=0.01. Grey shading shows the running decadal mean of temperature and the standard error of the running decadal mean of δ18O. b, Probability from a one-tailed t-test that decadal mean West Antarctic δ18O centred on any given year is as elevated as the decade of the 1990s (1991–2000). The dashed line shows the number of records contributing to each decadal mean.

  3. Decade-average
[delta]18O from the WAIS Divide ice core for the past 2,000 years.
    Figure 3: Decade-average δ18O from the WAIS Divide ice core for the past 2,000 years.

    Grey shading shows 2 s.d. about the decadal mean, based on the upper 100 years of the multi-core δ18O composite, providing an estimate of the 95% confidence range. The dashed line shows the 97.5 percentile value relative to the average linear trend.

  4. Modelled versus observed West Antarctic
[delta]18O and tropical SSTs.
    Figure 4: Modelled versus observed West Antarctic δ18O and tropical SSTs.

    a, Difference in mean simulated decadal-mean δ18O in Antarctic precipitation between 1991 and 2000 and the three preceding decades. b, Model range (2 s.d., grey shading) of simulated annual mean δ18O in precipitation averaged over West Antarctica compared with observed δ18O anomalies (black line). In both a and b, the model simulations are from 10-member ensembles of ECHAM4.6 simulations forced by global tropical SST with a slab ocean in the extratropics. c, SST anomalies26 averaged over the central tropical Pacific Niño4 region (thin solid line) and over the entire tropics (thick line), 1880–2009.


  1. Rignot, E. et al. Recent Antarctic ice mass loss from radar interferometry and regional climate modelling. Nature Geosci. 1, 106110 (2008).
  2. Thoma, M., Jenkins, A. & Holland, D. Modelling circumpolar deep water intrusions on the Amundsen Sea continental shelf, Antarctica. Geophys. Res. Lett. 35, L18602 (2008).
  3. Jenkins, A. et al. Observations beneath Pine Island Glacier in West Antarctica and implications for its retreat. Nature Geosci. 3, 468472 (2010).
  4. Steig, E. J. et al. Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year. Nature 457, 459462 (2009).
  5. Comiso, J. C. & Nishio, F. Trends in the sea ice cover using enhanced and compatible AMSR-E, SSM/I, and SMMR data. J. Geophys. Res. 113, C02S07 (2008).
  6. Orsi, A. J., Cornuelle, B. D. & Severinghaus, J. P. Little Ice Age cold interval in West Antarctica: Evidence from borehole temperature at the West Antarctic Ice Sheet (WAIS) Divide. Geophys. Res. Lett. 39, L09710 (2012).
  7. Bromwich, D. H. et al. Central West Antarctica among the most rapidly warming regions on Earth. Nature Geosci. 6, 139145 (2013).
  8. Steig, E. J., Ding, Q., Battisti, D. S. & Jenkins, A. Tropical forcing of Circumpolar Deep Water Inflow and outlet glacier thinning in the Amundsen Sea Embayment, West Antarctica. Annal. Glaciol. 53, 1928 (2012).
  9. Schneider, D. P., Deser, C. & Okumura, Y. An assessment and interpretation of the observed warming of West Antarctica in the austral spring. Clim. Dyn. 38, 323347 (2011).
  10. Ding, Q., Steig, E. J., Battisti, D. S. & Küttel, M. Winter warming in West Antarctica caused by central tropical Pacific warming. Nature Geosci. 4, 398403 (2011).
  11. Küttel, M., Steig, E. J., Ding, Q., Battisti, D. S. & Monaghan, A. J. Seasonal climate information preserved in West Antarctic ice core water isotopes: Relationships to temperature, large-scale circulation, and sea ice. Clim. Dyn. 39, 18411857 (2012).
  12. Noone, D. & Simmonds, I. Sea ice control of water isotope transport to Antarctica and implications for ice core interpretation. J. Geophys. Res. 109, D07105 (2004).
  13. Neumann, T. A. et al. Holocene accumulation and ice sheet dynamics in central West Antarctica. J. Geophys. Res. 113, F02018 (2008).
  14. Mulvaney, R. et al. Recent Antarctic Peninsula warming relative to Holocene climate and ice shelf history. Nature 489, 141144 (2012).
  15. Ding, Q., Steig, E. J., Battisti, D. S. & Wallace, J. M. Influence of the tropics on the Southern Annular Mode. J. Clim. 25, 63306348 (2012).
  16. Thompson, D. W. J. et al. Signatures of the Antarctic ozone hole in Southern Hemisphere surface climate change. Nature Geosci. 4, 741749 (2011).
  17. Dixon, D. A. et al. An ice-core proxy for northerly air mass incursions into West Antarctica. Int. J. Climatol. 32, 14551465 (2012).
  18. Schneider, D. P. & Steig, E. J. Ice cores record significant 1940s Antarctic warmth related to tropical climate variability. Proc. Natl Acad. Sci. USA 105, 1215412158 (2008).
  19. Okumura, Y., Schneider, D. P., Deser, C. & Wilson, R. Decadal-interdecadal climate variability over Antarctica and linkages to the tropics: Analysis of ice core, instrumental, and tropical proxy data. J. Clim. 25, 74217441 (2012).
  20. Latif, M., Kleeman, R. & Eckert, C. Greenhouse warming, decadal variability, or El Niño? An attempt to understand the anomalous 1990s. J. Clim. 10, 22212239 (1997).
  21. McGregor, S., Timmermann, A. & Timm, O. A unified proxy for ENSO and PDO variability since 1650. Clim. Past 6, 117 (2010).
  22. Roeckner, E. et al. The Atmospheric General Circulation Model ECHAM-4: Model Description and Simulation of Present-Day Climate (Max Planck Institut für Meteorologie Report 218, 90, 1996).
  23. Hoffmann, G., Werner, M. & Heimann, M. Water isotope module of the ECHAM atmospheric general circulation model: A study on timescales from days to several years. J. Geophys. Res. 103, 1687116896 (1998).
  24. Vance, T. et al. A millennial proxy record of ENSO and eastern Australian rainfall from the Law Dome ice core, East Antarctica. J. Clim. 26, 710725 (2013).
  25. Dinezio, P. N. et al. Climate response of the equatorial Pacific to global warming. J. Clim. 22, 48734892 (2009).
  26. Solomon, A. & Newman, M. Reconciling disparate twentieth-century Indo-Pacific ocean temperature trends in the instrumental record. Nature Clim. Change 2, 691699 (2012).
  27. Collins, M. et al. The impact of global warming on the tropical Pacific Ocean and El Niño. Nature Geosci. 3, 391397 (2010).
  28. Miller, R. L., Schmidt, G. A. & Shindell, D. T. Forced annular variations in the 20th century Intergovernmental Panel on Climate Change Fourth Assessment Report models. J. Geophys. Res. 111, D18101 (2006).
  29. Deser, C., Phillips, A. S., Bourdette, V. & Teng, H. Uncertainty in climate change projections: The role of internal variability. Clim. Dyn. 38, 527546 (2012).
  30. Rignot, E., Velicogna, I., van den Broeke, M. R., Monaghan, A. & Lenaerts, J. Acceleration of the contribution of the Greenland and Antarctic ice sheets to sea level rise. Geophys. Res. Lett. 38, L05503 (2011).

Download references

Author information


  1. Quaternary Research Center and Department of Earth and Space Sciences, University of Washington, Seattle, Washington 98195, USA

    • Eric J. Steig,
    • Qinghua Ding,
    • Marcel Küttel,
    • Peter D. Neff,
    • Ailie J. E. Gallant,
    • Spruce W. Schoenemann,
    • Bradley R. Markle,
    • Tyler J. Fudge,
    • Andrew J. Schauer &
    • Rebecca P. Teel
  2. Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado 80303, USA

    • James W. C. White &
    • Bruce H. Vaughn
  3. Department of Geological Sciences, Brigham Young University, Provo, Utah 84602, USA

    • Summer B. Rupper,
    • Landon Burgener &
    • Jessica Williams
  4. NASA Goddard Space Flight Center, Code 615, Greenbelt, Maryland 20770, USA

    • Thomas A. Neumann
  5. Climate Change Institute and School of Earth and Climate Sciences, University of Maine, Orono, Maine 04469, USA

    • Paul A. Mayewski,
    • Daniel A. Dixon &
    • Elena Korotkikh
  6. Desert Research Institute, Reno, Nevada 89512, USA

    • Kendrick C. Taylor
  7. Laboratoire des Sciences du Climat et de l’Environnement, Centre d’Etudes de Saclay, Gif-sur-Yvette 91191, France

    • Georg Hoffmann
  8. Institute for Marine and Atmospheric Research, Utrecht University, Utrecht 3508 TC, Netherlands

    • Georg Hoffmann
  9. National Center for Atmospheric Research, Boulder, Colorado 80305, USA

    • David P. Schneider
  10. Present address: Antarctic Research Centre, Victoria University of Wellington, Wellington 6140, New Zealand

    • Peter D. Neff
  11. Present address: School of Geography and Environmental Science, Monash University, Clayton, Victoria 3800, Australia

    • Ailie J. E. Gallant


E.J.S., J.W.C.W., S.B.R., P.D.N., B.R.M., B.H.V., D.P.S., S.W.S., T.A.N., P.A.M., K.C.T., T.J.F., D.A.D. and E.K. conducted fieldwork and sample collection. P.D.N., A.J.S., R.P.T., B.H.V., E.K., E.J.S., D.P.S., J.W.C.W., S.B.R., L.B. and J.W. obtained the ice-core water-isotope data. G.H. provided code and assistance with the modelling. E.J.S. and Q.D. compiled the data, conducted the model experiments and calculations and wrote the paper. All authors contributed to the final manuscript text.

Competing financial interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to:

Author details

Supplementary information

PDF files

  1. Supplementary Information (2.8 MB)

    Supplementary Information

Additional data