Nature 462, 863-867 (17 December 2009) | doi:10.1038/nature08686; Received 27 February 2009; Accepted 11 November 2009

Probabilistic assessment of sea level during the last interglacial stage

Robert E. Kopp1,2, Frederik J. Simons1, Jerry X. Mitrovica3, Adam C. Maloof1 & Michael Oppenheimer1,2

  1. Department of Geosciences,
  2. Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, New Jersey 08544, USA
  3. Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA

Correspondence to: Robert E. Kopp1,2 Correspondence and requests for materials should be addressed to R.E.K. (Email:


With polar temperatures ~3–5°C warmer than today, the last interglacial stage (~125kyr ago) serves as a partial analogue for 1–2°C global warming scenarios. Geological records from several sites indicate that local sea levels during the last interglacial were higher than today, but because local sea levels differ from global sea level, accurately reconstructing past global sea level requires an integrated analysis of globally distributed data sets. Here we present an extensive compilation of local sea level indicators and a statistical approach for estimating global sea level, local sea levels, ice sheet volumes and their associated uncertainties. We find a 95% probability that global sea level peaked at least 6.6m higher than today during the last interglacial; it is likely (67% probability) to have exceeded 8.0m but is unlikely (33% probability) to have exceeded 9.4m. When global sea level was close to its current level (≥-10m), the millennial average rate of global sea level rise is very likely to have exceeded 5.6mkyr-1 but is unlikely to have exceeded 9.2mkyr-1. Our analysis extends previous last interglacial sea level studies by integrating literature observations within a probabilistic framework that accounts for the physics of sea level change. The results highlight the long-term vulnerability of ice sheets to even relatively low levels of sustained global warming.


These links to content published by NPG are automatically generated.


Global change Interglacial and future sea level

Nature News and Views (17 Dec 2009)