SNOWBALL EARTH Our image of the planet Earth is often one of a tender, protective matriarch. Recent scientific findings have led us to revise this notion. "Mother Earth," it seems, has not been such a fond protector, but quite the opposite. In fact, in its more than 4-billion-year history, our planet has been home to repeated violent climactic changes, which have caused mass extinctions. And yet, these same catastrophes also helped bring about the evolution of life on earth from the simplest microbes to the complexity and diversity that is found on the planet today. Featuring location footage, interviews with the world's foremost scientists and cutting-edge computer technology, Miracle Planet is a five-part series that recounts the profound and gripping story of Earth's mysterious evolution. Narrated by Christopher Plummer, it also reveals the surprising role that sheer chance has played in the development of life. Miracle Planet Episode 1 The Violent Past Part 1/4 HD Geological and palaeomagnetic studies indicate that ice sheets may have reached the Equator at the end of the Proterozoic eon, 800 to 550 million years ago, leading to the suggestion of a fully ice-covered 'snowball Earth'. Climate model simulations indicate that such a snowball state for the Earth depends on anomalously low atmospheric carbon dioxide concentrations, in addition to the Sun being 6 per cent fainter than it is today. However, the mechanisms producing such low carbon dioxide concentrations remain controversial. Here we assess the effect of the palaeogeographic changes preceding the Sturtian glacial period, 750 million years ago, on the long-term evolution of atmospheric carbon dioxide levels using the coupled climate–geochemical model GEOCLIM. In our simulation, the continental break-up of Rodinia leads to an increase in runoff and hence consumption of carbon dioxide through continental weathering that decreases atmospheric carbon dioxide concentrations by 1,320 p.p.m. This indicates that tectonic changes could have triggered a progressive transition from a 'greenhouse' to an 'icehouse' climate during the Neoproterozoic era. When we combine these results with the concomitant weathering effect of the voluminous basaltic traps erupted throughout the break-up of Rodinia11, our simulation results in a snowball glaciation. Thanks Magik