The last Ice Age, known as the Pleistocene Epoch, began almost 1.8 million years ago and lasted until approximately 11,700 years ago. During this time, massive glaciers covered most of the surface of the Earth. There have been four known Ice Ages on Earth in the 4.6 billion years that the planet has existed. It is very possible that there were many more that occurred that are undocumented from before the advent of mankind, about 2.3 million years ago.
As the last Ice Age ended, the Antarctic ice sheets began to melt. This caused waters to rise, drowning previously raised sections of the continents. The moving water gradually heated up and caused a rise in the temperatures of many different areas, creating the beginnings of the climate enjoyed by humans today. The Pleistocene Epoch is the first known Ice Age to involve humans, or homo sapiens. During this time period, humans continued to evolve. By the end of the Ice Age, human beings were spread all over the planet. The Pleistocene Epoch was the first epoch in the Quaternary Period and the sixth epoch of the Cenozoic Era. The Earth is now in a period known as the Holocene Epoch.