Last interglacial Arctic warmth confirms polar amplification of climate change.

Anderson, P., Bennike, O., Bigelow, N., Brigham-Grette, J., Duvall, M., Edwards, M., Fréchette, B., Funder, S., Johnsen, Sigfus, Knies, J., Koerner, R., Lozhkin, A., Marschall, S., Matthiessen, J., Macdonald, G., Miller, G., Montoay, M., Muhs, D., Otto-Bliesner, B., Overpeck, J., Reeh, N., Sejrup, H.-P., Spielhagen, Robert, Turner, C. and Velichko, A and CAPE-Last Interglacial Project Members (2006) Last interglacial Arctic warmth confirms polar amplification of climate change. Quaternary Science Reviews, 25 . pp. 1383-1400.

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Abstract

The warmest millennia of at least the past 250,000 years occurred during the Last Interglaciation, when global ice volumes were similar to or smaller than today and systematic variations in Earth's orbital parameters aligned to produce a strong positive summer insolation anomaly throughout the Northern Hemisphere. The average insolation during the key summer months (M, J, J) was ca 11% above present across the Northern Hemisphere between 130,000 and 127,000 years ago, with a slightly greater anomaly, 13%, over the Arctic. Greater summer insolation, early penultimate deglaciation, and intensification of the North Atlantic Drift, combined to reduce Arctic Ocean sea ice, allow expansion of boreal forest to the Arctic Ocean shore across vast regions, reduce permafrost, and melt almost all glaciers in the Northern Hemisphere. Insolation, amplified by key boundary condition feedbacks, collectively produced Last Interglacial summer temperature anomalies 4–5 °C above present over most Arctic lands, significantly above the average Northern Hemisphere anomaly. The Last Interglaciation demonstrates the strength of positive feedbacks on Arctic warming and provides a potentially conservative analogue for anticipated future greenhouse warming.

Document Type: Article
Keywords: Climate change, Arctic warmth, polar amplification
Research affiliation: OceanRep > GEOMAR > FB1 Ocean Circulation and Climate Dynamics > FB1-P-OZ Paleo-Oceanography
Refereed: Yes
Open Access Journal?: No
Publisher: Elsevier
Projects: CAPE
Date Deposited: 27 Nov 2009 09:07
Last Modified: 16 Sep 2016 12:38
URI: https://oceanrep.geomar.de/id/eprint/4123

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