Orbital and CO2 forcing of late Paleozoic continental ice sheets
Article first published online: 11 OCT 2007
Copyright 2007 by the American Geophysical Union.
Geophysical Research Letters
Volume 34, Issue 19, October 2007
How to Cite
2007), Orbital and CO2 forcing of late Paleozoic continental ice sheets, Geophys. Res. Lett., 34, L19708, doi:10.1029/2007GL031188., , and (
- Issue published online: 11 OCT 2007
- Article first published online: 11 OCT 2007
- Manuscript Accepted: 30 AUG 2007
- Manuscript Revised: 28 AUG 2007
- Manuscript Received: 30 JUN 2007
- ice sheets;
 Contrasting views of the size, duration, and history of the Gondwanan continental ice sheets have been proposed from late Paleozoic glaciological and sedimentological evidence. To evaluate these differing views, a coupled ice sheet-climate model is used to simulate continental ice sheets under a wide range of late Paleozoic orbital and pCO2 conditions. The model experiments indicate that orbital variations at pCO2 concentrations below 2X pre-industrial atmospheric levels (PAL; 280 ppm) produce large changes in late Paleozoic ice volume (∼1.3 × 108 km3) and sea level (∼20 to 245 m). Between 2 and 8X PAL Gondwana continental ice is simulated only under the most extreme Southern Hemisphere cold summer orbit, but still produces significant ice volumes (∼8–12 × 107 km3). Our results highlight the important role of atmospheric CO2 in determining the distribution, volume, and stability of late Paleozoic ice sheets, factors that ultimately impacted sea level, cyclothem deposition, and global climate, and reconcile disparate views of the Late Paleozoic Ice Age.