Storm of fire, ice led to 'snowball Earth' 70 crore yrs ago
Harvard scientists have proposed that a combination of erupting volcanoes and rapid cooling effect may have caused 'snowball Earth', the largest ever glaciation event in Earth's history. The sulphur-rich volcanic bursts reached upper atmosphere blocking solar radiation while the existing ice reflected the entering sunlight, further cooling the planet and snowballing it over 70 crore years ago.