100,000-Year Climate Cycle Explained | History for Sleep

Imagine a world 6°C colder. Seem insignificant? That small shift plunged Earth into a glacial period. Massive ice sheets swallowed continents. Sea levels plummeted 100 meters. You could walk from Asia to Alaska. We are technically still in an ice age, the Pleistocene, begun 2.6 million years ago. Within it, 100,000-year cycles dictate glacial and interglacial phases. Our current interglacial has lasted 11,700 years. But what drives this relentless planetary rhythm? A Serbian scientist, Milutin Milankovitch, unlocked the key: subtle shifts in Earth's orbit, tilt, and wobble. These cycles—eccentricity, obliquity, precession—alter sunlight distribution, triggering runaway ice ages. The weakest cycle, eccentricity, strangely dominates. How does a tiny nudge unleash such colossal change? Explore the science, the vanished megafauna, and the future of our frozen world. 00:00 – The Lost World of Ice Age Giants 02:15 – What is an Ice Age, Really? 05:30 – The Last Glacial Maximum 10:45 – 6°C: The Temperature That Changed Everything 16:00 – Milankovitch Cycles: Earth's Orbital Rhythms 23:30 – Eccentricity: The 100,000-Year Mystery 31:00 – Obliquity and Precession: The Other Climate Drivers 38:00 – Northern Hemisphere Summers: The Ice Age Trigger 45:00 – Megafauna: Life in the Frozen World 52:30 – Humans vs. Ice: Survival and Adaptation