Download This PaperRevisiting the Causes of the Neoproterozoic Snowball Earth
38 Pages Posted: 22 Jun 2020
Date Written: April 27, 2020
Abstract
In the Neoproterozoic Era, the Earth experienced two broad intervals of global glaciation, commonly known as Snowball Earth. There was also a rapid diversification of life, with the evolution of most of the eukaryotic lineages. Here, salient evidence for the Neoproterozoic global glaciations, including the carbon isotope record, is reinterpreted and an alternative explanation for the causes of glaciation is provided. The proliferation of life could have led to increases in atmospheric O2 levels and concomitant decreases in CO2 and CH4. Coupled biochemical and geochemical changes would have led to global cooling and glaciation. This so-called biotic hypothesis of the Snowball Earth is consistent with the most salient features of the reported evidence and explains the consecutive global glaciations.
Keywords: Snowball Earth; Oxygenic photosynthesis; Neoproterozoic glaciation; Atmospheric gases; Co-Evolution of Earth and Life
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