ANCIENT continents ripping apart might have turned the world into a giant ice sheet, according to a new climate model. The finding provides a simple mechanism for global cooling that would explain the controversial “Snowball Earth” theory, which proposes that the oceans froze over at least twice between 550 and 800 million years ago.
The supercontinents from which the present continents arose had extremely dry interiors. Yannick Donnadieu at the French National Centre for Scientific Research (CNRS) in Gif-sur-Yvette and his colleagues found that the break-up of one such giant land mass 750 million years ago would have triggered extra…
