How Basalt Weathering and CO2 Cycles Caused the Snowball Earth Ice Age

Harvard researchers have proposed a new model for the Sturtian glaciation, suggesting Earth did not stay frozen for 56 million years straight. Instead, the planet likely cycled between total ice cover and warm intervals, driven by the interaction between volcanic carbon dioxide and the weathering of basalt rocks. This limit cycle theory explains how oxygen levels remained high enough for aerobic life to survive, as intermittent thaws allowed marine productivity to replenish the atmosphere. The findings highlight the complex relationship between the global carbon cycle and planetary temperature stability.