TY - JOUR
T1 - Methane and climate during the Precambrian era
AU - Kasting, James F.
N1 - Funding Information:
Different parts of this work were supported by grants from NASA's Exobiology program, the NASA Astrobiology Institute, and NSF's LExEn program.
PY - 2005/6/30
Y1 - 2005/6/30
N2 - The Sun was substantially less bright in the distant past, yet Earth's surface temperature remained above freezing. Higher concentrations of the greenhouse gases CO2 and CH4 were likely responsible for keeping the early climate warm. CH4 concentrations of 1000 ppm or higher are predicted for the Late Archean/Paleoproterozoic atmosphere prior to the rise of O2. Photolysis of this CH4 may have created an optically thin organic haze during much of this time. The rise of O2 at 2.3 Ga eliminated most of the methane and probably triggered the Paleoproterozoic glaciations. CH4 concentrations could have remained elevated throughout much of the Proterozoic, however, as a consequence of low concentrations of dissolved O2 and sulfate in the deep oceans and a corresponding increase in organic matter recycling by fermentation and methanogenesis.
AB - The Sun was substantially less bright in the distant past, yet Earth's surface temperature remained above freezing. Higher concentrations of the greenhouse gases CO2 and CH4 were likely responsible for keeping the early climate warm. CH4 concentrations of 1000 ppm or higher are predicted for the Late Archean/Paleoproterozoic atmosphere prior to the rise of O2. Photolysis of this CH4 may have created an optically thin organic haze during much of this time. The rise of O2 at 2.3 Ga eliminated most of the methane and probably triggered the Paleoproterozoic glaciations. CH4 concentrations could have remained elevated throughout much of the Proterozoic, however, as a consequence of low concentrations of dissolved O2 and sulfate in the deep oceans and a corresponding increase in organic matter recycling by fermentation and methanogenesis.
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U2 - 10.1016/j.precamres.2005.03.002
DO - 10.1016/j.precamres.2005.03.002
M3 - Article
AN - SCOPUS:31544483948
VL - 137
SP - 119
EP - 129
JO - Precambrian Research
JF - Precambrian Research
SN - 0301-9268
IS - 3-4
ER -