During an ice age, the temperature of the Earth gradually warms up, causing glaciers to retreat. Eventually, the temperatures will begin getting colder, causing the glaciers to advance. As such, warmer temperatures do not necessarily mark the end of an ice age.
Scientists now know that Earth is in the middle of the most recent ice age, which began about 3 million years ago.There have been at least five ice ages in Earth's history. Around 20,000 years ago, Earth was at its coldest and today, temperatures are around 10 degrees warmer than they were back then.Learn more about Prehistory