Kathleen Buckleys age 9s of Philadelphia, PA. for her question;

What caused the Ice Age?

The earth has lived through four Ice Ages. The last one melted away some 20,000 years ago, There were human beings there to see it go, They saw the ice turn into teeming rivers and floods of water,

An Ice Age need not be extremely colds Suppose a summer is too cool to melt all the winter’s snow, If this went on the snows of many years would pile up end pack into glaciers. The glaciers would grow and cover more and more land until warmer summers returned to stop them,

No one knows for sure what caused the temperature to drop those few necessary degrees. At one time, it was thought the earth moved a little further from the sun, Another idea is that the sun cooled off for a spell, Another, no more than a guess, blames it on volcanic dust, Dust in the air steals heat meant for the earth, Enough volcanic dust might lower the temperature enough to cause an Ice Age, However no one has definitely proved what caused these long long winters.