For a minimum of twice in the history of our planet, which is incredibly extensive if we consider for how a short amount of time we have exited, almost the whole planet was covered in a thick sheet of ice and snow. These vents were absolutely dramatic and they were known as Snowball Earths, occurring in a very quick succession about 700 millions years ago. The proof we have at the moment suggest the fact that these consecutive global ice ages prepared our planet for the incredible explosion that would turn out to be the appearance of multicellular life on Earth.
Multiple Factors
Researchers have also looked at the possibility of there being multiple scenarios regarding what might have tipped our planet into going to its ice age. Of course, there is no clear path that has already been set, but the scientific community has reached a consensus, according to which it has been assumed the fact that there are some temporary freeze-overs which have happened within such a timing that they have managed to push the planet beyond its critical threshold, thus reducing the amount of sunlight there is and the amount of carbon dioxide that can be found in the atmosphere to such a low level, that a global expansion of ice has naturally occurred.
New Theory
Now, scientists affiliated with MIT have decided to say that Snowball Earth are, most probably, the product of something known as rate-induced glaciations, Essentially, researchers argue the fact that the Earth can be sent into an entirely global ice age simply through the level of solar radiation that gets there, if the amount changes quickly over a relatively short period of time. That means that solar radiation does not have to drop below a certain point: it simply has to drop fast enough to cause a global ice age.
