Quantifying ice-sheet feedbacks during the last glacial inception

Abstract

The last glacial inception (∼116 ky ago) has long been used to test the sensitivity of climate models to insolation. From these simulations, atmospheric, oceanic and vegetation feedbacks have been shown to amplify the initial insolation signal into a rapid growth of ice-sheets over the northern hemisphere. However, due to the lack of comprehensive atmosphere-ocean-vegetation-northern hemisphere ice-sheet models, the impact of all these feedbacks acting concurrently has not yet been evaluated. Here we present the results from such a model, which simulates significant ice-sheet growth over North America, but none over Eurasia. Our analyses focus on the different behaviours over these regions, and the quantification of the ice-sheet feedbacks on climate. Copyright 2004 by the American Geophysical Union.