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Clouds and Snowball Earth deglaciation
Author(s) -
Abbot Dorian S.,
Voigt Aiko,
Branson Mark,
Pierrehumbert Raymond T.,
Pollard David,
Le Hir Guillaume,
Koll Daniel D. B.
Publication year - 2012
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2012gl052861
Subject(s) - deglaciation , snowball earth , geology , earth system science , climatology , earth science , physical geography , oceanography , glacial period , paleontology , geography
Neoproterozoic, and possibly Paleoproterozoic, glaciations represent the most extreme climate events in post‐Hadean Earth, and may link closely with the evolution of the atmosphere and life. According to the Snowball Earth hypothesis, the entire ocean was covered with ice during these events for a few million years, during which time volcanic CO 2 increased enough to cause deglaciation. Geochemical proxy data and model calculations suggest that the maximum CO 2 was 0.01–0.1 by volume, but early climate modeling suggested that deglaciation was not possible at CO 2 = 0.2. We use results from six different general circulation models (GCMs) to show that clouds could warm a Snowball enough to reduce the CO 2 required for deglaciation by a factor of 10–100. Although more work is required to rigorously validate cloud schemes in Snowball‐like conditions, our results suggest that Snowball deglaciation is consistent with observations.