Geologists have long been intrigued by the presence of traces of very ancient glaciers in many parts of the globe, including those at the equator.
What is the age of the glaciers? It turned out very solid, from 800 to 550 million years.
At the end of the twentieth century, drawing on the accumulated knowledge of science, Paul Hoffman and Daniel Shreg from Harvard University (USA) put forward the hypothesis that in the Proterozoic era, the globe has repeatedly covered by thick ice.
This hypothesis was briefly called “Earth – snowball.” Approximately 750 million years ago the ice came down to the equator, while the average temperature of the globe has dropped to – 40 degrees Celsius.
Fortunately for life on the planet, the Earth did not stay icy.
Despite the ice, continued volcanic activity, supplying the atmosphere with carbon dioxide.
Finally, the climate was very hot: the average temperature has risen to 25-30 degrees.
Evolution moved on …