Australia: The Land Where Time Began

A biography of the Australian continent 

Polar Amplification of Climate Change Confirmed by the Warmth of the Arctic in the Last Interglacial

The last interglacial was the warmest period in at least the last 250,000 years with the global volume of ice being equal to, or smaller than, global volume of ice at the present, at a time when systematic variations of orbital parameters of the Earth aligned resulting in a strong positive summer insolation anomaly throughout the Northern hemisphere. Between 130,000 and 127,000 BP the average insolation during the key summer months (M,J,J) was about 11 % higher than at the present, and a slightly greater anomaly, 13 % over the Arctic. Sea ice in the Arctic Ocean was reduced, allowing the expansion of boreal forests as far as the shore of the Arctic Ocean across vast regions, the reduction of permafrost, and the melting of almost all glaciers in the Northern Hemisphere. Key boundary condition feedbacks amplified insolation to produce temperature anomalies of 4-5oC higher than at the present over most of the area of Arctic land, significantly higher than the Northern Hemisphere anomaly. The strength of positive feedbacks in warming of the Arctic during the last interglacial provides an analogue for the anticipated greenhouse warming in the future.

 

Sources & Further reading

  1. "Last Interglacial Arctic Warmth Confirms Polar Amplification of Climate Change." Quaternary Science Reviews 25, no. 1314 (7// 2006): 1383-400.
Author: M. H. Monroe
Email: admin@austhrutime.com
Last updated: 29/03/2013
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                                                                                           Author: M.H.Monroe  Email: admin@austhrutime.com     Sources & Further reading