Ice ages

A reconstruction of the Anglian ice sheet

During the last 2.6 million years or so in the Quaternary period, ice ages, also called glacial ages, were times of extreme cooling of the Earth's climate where ice sheets and other types of glacier expanded to cover large areas of land. Between ice ages there were warmer interglacial periods and we are now living during such a time.

There have been many ice ages during the last 2.6 million years but when people talk about the Ice Age, they are often referring to the most recent glacial period, which peaked about 21,000 years ago and ended about 11,500 years ago.

What causes ice ages is not completely understood. The composition of the atmosphere, changes in the position of our planet around the Sun, and changes in ocean currents are some of the important factors that control the climate.

Image: A reconstruction of the Anglian ice sheet in Precambrian North London (credit: The Natural History Museum, London)

Introduction

A reconstruction of the Anglian ice sheet Ice ages

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