首页|Atmospheric oxygenation as a potential trigger for climate cooling

Atmospheric oxygenation as a potential trigger for climate cooling

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Secular changes in atmospheric CO2 and consequent global climate variations,are commonly attributed to global outgassing and the efficiency of silicate weathering,which may have been linked to mountain formation,land/arc distribution,and plant colonization through geological time.Although oxidative weathering has been shown to exert a significant role in the propagation of weathering fronts through the oxidation of Fe-bearing minerals,the influence of atmospheric O2 concentration(pO2)on silicate weathering,CO2 consumption,and global climate has not been thoroughly evaluated.This study presents a numerical model aimed at estimating the effects of pO2 on the climate,considering the influence of pO2 on the regolith thickness and thus weathering duration of granitic domains.Our model simulations reveal that an increase in weathering efficiency,through deeper penetration of the oxidative weathering front in the granitic regolith,would independently introduce a steady-state climate cooling of up to~8 ℃,in step with one-order of magnitude rise in pO2.This temperature change may have repeatedly initiated the run-away ice-albedo feedback,leading to global glacial events(e.g.,Neoproterozoic Snowball Earth).Increasing granitic weathering efficiency caused by a substantial pO2 increase may also have contributed to the development of icehouse climate during the Phanerozoic.

Atmospheric oxygenationWeathering frontCarbon cycleGlaciationSnowball Earth

Guang-Yi Wei、Gaojun Li

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School of Earth Sciences and Engineering,and Frontiers Science Center for Critical Earth Material Cycling,Nanjing University,Nanjing 210023,China

2024

科学通报(英文版)
中国科学院

科学通报(英文版)

CSTPCD
ISSN:1001-6538
年,卷(期):2024.69(23)