Editor's Summary
6 December 2007
Snowball Earth avoided
The 'snowball Earth' hypothesis proposes that the Earth was fully covered with ice at times during the Neoproterozoic. Conditions that allow open water in equatorial regions to coexist with snowball conditions elsewhere — a 'slushball' — have been proposed as an alternative, but the issue remains controversial. Peltier et al. present a model study of the coupled evolution of the carbon cycle and the climate system during the Neoproterozoic. They find that as surface temperatures fall, a draw-down of atmospheric oxygen into the ocean increases the rate of remineralization of a massive pool of dissolved organic carbon. This leads to elevated atmospheric CO2, more greenhouse warming, and the prevention of a full-blown snowball state.
News and Views: Palaeoclimate: Slush find
A coupled model of palaeoclimate and carbon cycling turns up the heat on the idea that Earth once became a giant snowball. It supports instead a milder 'slushball Earth' history — but piquant questions remain.
Alan J. Kaufman
doi:10.1038/450807a
Article: Snowball Earth prevention by dissolved organic carbon remineralization
W. Richard Peltier, Yonggang Liu & John W. Crowley
doi:10.1038/nature06354
Abstract | Full Text | PDF (2,239K) | Supplementary information