Part 6/10:

Scientists have proposed various reasons for these glaciations, ranging from astronomical impacts altering Earth's axial tilt to a passage through cosmic dust clouds that increased reflectivity, preventing sunlight from warming the planet. However, the simplest hypothesis also proved the most compelling—the fluctuating greenhouse effect. Increased volcanic activity contributed to greenhouse gas emissions, while subsequent cooling periods reduced their presence, setting off a destructive cycle.

How did Earth escape from this icy grip? As glaciation persisted, volcanic activity continued to pump carbon dioxide into the atmosphere, ultimately leading to a gradual warming and melting of the ice, transitioning the planet back to habitable conditions.