From Science Daily:
ScienceDaily (Dec. 8, 2008) — The planet’s present day greenhouse scourge, carbon dioxide, may have played a vital role in helping ancient Earth to escape from complete glaciation, say scientists in a paper published online today.
In their review for Nature Geoscience, UK scientists claim that the Earth never froze over completely during the Cryogenian Period, about 840 to 635 million years ago.
This is contrary to the Snowball Earth hypothesis, which envisages a fully frozen Earth that was locked in ice for many millions of years as a result of a runaway chain reaction that caused the planet to cool.
Read more ….
My Comment: I live half of the time up north in the Laurentians of Quebec. It is -22C. outside right now. Hmmmm …. more carbon dioxide please.