Article abstract


Nature Geoscience 1, 620 - 624 (2008)
Published online: 31 August 2008 | doi:10.1038/ngeo285

Subject Categories: Climate science | Cryospheric science | Palaeoclimate and palaeoceanography

Rapid early Holocene deglaciation of the Laurentide ice sheet

Anders E. Carlson1, Allegra N. LeGrande2, Delia W. Oppo3, Rosemarie E. Came4, Gavin A. Schmidt2, Faron S. Anslow5, Joseph M. Licciardi6 & Elizabeth A. Obbink1


The demise of the Laurentide ice sheet during the early Holocene epoch is the most recent and best constrained disappearance of a large ice sheet in the Northern Hemisphere, and thus allows an assessment of rates of ice-sheet decay as well as attendant contributions to sea level rise. Here, we use terrestrial and marine records of the deglaciation to identify two periods of rapid melting during the final demise of the Laurentide ice sheet, when melting ice contributed about 1.3 and 0.7 cm of sea level rise per year, respectively. Our simulations with a fully coupled ocean–atmosphere model suggest that increased ablation due to enhanced early Holocene boreal summer insolation was the predominant cause of Laurentide ice-sheet retreat. Although the surface radiative forcing in boreal summer during the early Holocene is twice as large as the greenhouse-gas forcing expected by the year 2100, the associated increase in summer surface air temperatures is very similar. We conclude that our geologic evidence for a rapid retreat of the Laurentide ice sheet may therefore describe a prehistoric precedent for mass balance changes of the Greenland ice sheet over the coming century.

Top
  1. Department of Geology and Geophysics, University of Wisconsin, Madison, Wisconsin 53706, USA
  2. NASA Goddard Institute for Space Studies and Center for Climate System Research, Columbia University, New York 10025, USA
  3. Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
  4. Geology and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
  5. Earth and Ocean Sciences, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
  6. Department of Earth Sciences, University of New Hampshire, Durham, New Hampshire 03824, USA

Correspondence to: Anders E. Carlson1 e-mail: acarlson@geology.wisc.edu



MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.

NEWS AND VIEWS

Ancient tropical methane

Nature News and Views (02 Dec 1993)

Linking ice-core records to ocean circulation

Nature News and Views (22 Sep 1994)

See all 4 matches for News And Views