<Li> A polar sea is almost land - locked, as the Arctic Ocean is today . </Li> <Li> A supercontinent covers most of the equator, as Rodinia did during the Cryogenian period . </Li> <P> Since today's Earth has a continent over the South Pole and an almost land - locked ocean over the North Pole, geologists believe that Earth will continue to experience glacial periods in the geologically near future . </P> <P> Some scientists believe that the Himalayas are a major factor in the current ice age, because these mountains have increased Earth's total rainfall and therefore the rate at which carbon dioxide is washed out of the atmosphere, decreasing the greenhouse effect . The Himalayas' formation started about 70 million years ago when the Indo - Australian Plate collided with the Eurasian Plate, and the Himalayas are still rising by about 5 mm per year because the Indo - Australian plate is still moving at 67 mm / year . The history of the Himalayas broadly fits the long - term decrease in Earth's average temperature since the mid-Eocene, 40 million years ago . </P>

What were the temperatures during the ice age