When the Entire Earth Froze for 50 Million Years

700 million years ago, ice covered our whole planet — even the equator. The oceans froze under ice up to a kilometer thick, the average temperature fell to around −50°C, and it lasted for more than 50 million years. So how did Earth escape? And why might this frozen nightmare be the reason animals — and you — exist? This is the story of Snowball Earth. CHAPTERS 0:00 Standing on a frozen equator 0:44 The rocks that made no sense 2:17 The planet-sized mirror 3:34 How the world froze 4:43 A day on Snowball Earth 5:45 Life holds its breath 6:39 The great escape 8:36 It happened twice 9:38 Could it happen again? SOURCES Hoffman, P. F., Kaufman, A. J., Halverson, G. P., Schrag, D. P. (1998). A Neoproterozoic Snowball Earth. Science 281, 1342–1346. Hoffman, P. F. et al. (2017). Snowball Earth climate dynamics and Cryogenian geology-geobiology. Science Advances 3, e1600983. Kirschvink, J. L. (1992). Late Proterozoic low-latitude global glaciation: the Snowball Earth. In: The Proterozoic Biosphere, Cambridge University Press. Harland, W. B. (1964). Critical evidence for a great Infra-Cambrian glaciation. Geologische Rundschau 54, 45–61. Budyko, M. I. (1969). The effect of solar radiation variations on the climate of the Earth. Tellus 21, 611–619. Rooney, A. D. et al. (2015). A Cryogenian chronology: Two long-lasting synchronous Neoproterozoic glaciations. Geology 43, 459–462. Macdonald, F. A. et al. (2010). Calibrating the Cryogenian. Science 327, 1241–1243. Pierrehumbert, R. T. et al. (2011). Climate of the Neoproterozoic. Annual Review of Earth and Planetary Sciences 39, 417–460. All animation, narration script and graphics are original. Dates and numbers are scientific estimates and are still being researched. #SnowballEarth #EarthHistory #Geology