W. J. D'Andrea et al., PNAS (May 31, 2011), Abrupt Holocene climate change as an important factor for human migration in West Greenland

Proceedings of the National Academy of Sciences, published online before print May 31, 2011; doi: 10.1073/pnas.1101708108

Abrupt Holocene climate change as an important factor for human migration in West Greenland

1. William J. D’Andrea^a,¹,², 
2. Yongsong Huang^a,², 
3. Sherilyn C. Fritz^b and
4. N. John Anderson^c

1. ^aDepartment of Geological Sciences, Brown University, Providence, RI 02912;
2. ^bDepartment of Earth and Atmospheric Sciences and School of Biological Sciences, University of Nebraska, Lincoln, NE 68588;
3. ^cDepartment of Geography, Loughborough University, Leics LE11 3TU, United Kingdom

1. Edited by Julian Sachs, University of Washington, Seattle, WA, and accepted by the Editorial Board April 22, 2011 (received for review January 31, 2011)

Abstract

West Greenland has had multiple episodes of human colonization and cultural transitions over the past 4,500 y. However, the explanations for these large-scale human migrations are varied, including climatic factors, resistance to adaptation, economic marginalization, mercantile exploration, and hostile neighborhood interactions. Evaluating the potential role of climate change is complicated by the lack of quantitative paleoclimate reconstructions near settlement areas and by the relative stability of Holocene temperature derived from ice cores atop the Greenland ice sheet. Here we present high-resolution records of temperature over the past 5,600 y based on alkenone unsaturation in sediments of two lakes in West Greenland. We find that major temperature changes in the past 4,500 y occurred abruptly (within decades), and were coeval in timing with the archaeological records of settlement and abandonment of the Saqqaq, Dorset, and Norse cultures, which suggests that abrupt temperature changes profoundly impacted human civilization in the region. Temperature variations in West Greenland display an antiphased relationship to temperature changes in Ireland over centennial to millennial timescales, resembling the interannual to multidecadal temperature seesaw associated with the North Atlantic Oscillation.

¹Present address: Department of Geosciences, University of Massachusetts, Amherst, MA 01003.

²Correspondence e-mail: dandrea@geo.umass.edu or yongsong_huang@brown.edu.

http://www.pnas.org/content/early/2011/05/23/1101708108