We tend to think of the Ice Age as being in the distant past, millions of years ago when glaciers covered the planet, scouring out the great glens of the Scottish Highlands, as woolly mammoths roamed the tundra of northern Europe and the Americas. While the last glacial period is in the past, amazingly we are still officially in an Ice Age! We are just in a warm, interglacial phase.
The Earth’s temperature has varied widely and there have been times when there was hardly a trace of any ice even at the poles, while in the glacial periods the whole planet has practically been impacted in a thick icy sheath. The current intergalcial period begain about 10,000 years ago and allowed the growth of human civilizations as people settled down and agricultural societies developed.
Our planet has probably seen at least 5 major Ice Ages in the past 3 billion years, the first being more than 2 billion years ago and lasted around 220 million years. Each subsequent Ice Age lasted tens of millions of years although temperatures rise and fall during the Ice Age and the current one reached it’s coldest phase about 3 million years ago.
There is still scientific debate surrounding the effect that Ice Ages have had on the flora and fauna of the planet, including human development. There is also much to understand about what causes Ice Ages, with speculation about fluctuations in energy output from the Sun, changes in Earth’s distance from the Sun and geothermal activity inside the planet.
