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7 June 2016

Astounding Facts About the Ice Age

These days, if you want to see a glacier, you probably have to go on a bit of a voyage to do so. The hulking masses of ice currently cover about 10% of the Earth’s landmass, and a big portion of that is Greenland. When the last ice age, which happened during the Pleistocene, reached maximum intensity, 32% of the Earth’s total land area was encased in glacier ice.

The Pleistocene ended about 11,700 years ago, making it the last geological epoch before our current one (the Holocene). That’s less than the blink of an eye, relatively speaking, but the planet was a very, very different place back then. Across a huge portion of the planet, the landscape was cold, harsh, and teaming with wildlife on a scale we can scarcely imagine now.

Everything Was Bigger

There are plenty of big animals roaming around now, and we’re lucky enough to share our time on this planet with the largest animal that has ever existed – the blue whale, but the Pleistocene played host to a far stronger roster of massive land mammals in particular. It’s not known exactly why, but theories suggest that it was the result of an evolutionary arms race that began after the extinction of the dinosaurs 65 million years ago, and ended with the next mass extinction about 12,000 years ago.

Herbivores gradually gained size and strength to be better equipped to fight off predators, and they in turn grew to be able to hunt them. In a sense, we were the animal to break that cycle, as we remain the only animal to hunt big prey with tools (for the time being), eliminating the need for increased size and strength. More importantly, it’s fair easier to retain heat in extreme cold when you’re bigger, hence why so many arctic animals are so large.

Particularly incredible examples include the giant short-faced bear, which stood a full 3.5 metres tall on its hind legs and may have been able to reach running speeds of 65kph, the giant ground sloth, which also stood 3.5 metres tall and had a chainmail-like layer of bone, and the 2.4 metre long North American lion. The one we all know about remains the most impressive, though: the woolly mammoth. These massive, furry elephants could weigh up to 12 tonnes and possessed tusks which could be 1.5 metres long. They also survived longer than any other ice age giant, hanging around until about 1700 years ago.

It was all the Himalayas’ Fault

There is no mountain range quite as breath-taking as the Himalayas. It houses the highest peak on the planet and offers some of the most amazing views anyone could ever hope to see, but it might also be responsible for the last ice age. The Himalayas exist because, over the past 10 million years, the Indian subcontinent has been bashing shoulders with Asia like that one guy at every gig with no spatial awareness.

As a result of this, the Tibetan Plateau rose by more than 2 miles directly upwards, which as well as creating one of the greatest frontiers on the planet, had some other interesting side effects. The peaks are thought to have started the first Asian monsoons about 8 million years ago, which in turn heralded the lengthy dry seasons which much of Asia experiences each year. This, in turn, caused the Mongolian and Gobi deserts to form, creating dust which then blew eastward and collected in deposits in China.

This dusty period would have led to more intense winter monsoon seasons, strengthening the glacial cycles and contributing to the series of deep freezes that came and went between now and about 2.5 million years ago. Obviously there were many other factors, but this most certainly played into it.

We’ve Had Several ‘Mini Ice Ages’

It’s still up for debate whether or not the current ice age has actually, officially ended. The massive glaciers which defined it never fully went away, you can see them today, and we still experience cold, icy winters across much of the planet, a seasonal phenomenon which defined the previous epoch as much as it does this one. Even if we are still in an ice age, we’re on the downturn, and there’s certainly no cause for worry that it’ll suddenly plunge us in to another deep freeze.

What could happen again, and has happened a few times since, is a mini ice age. The most recent of these happened somewhere between the 12th and 14th century, and hit a particularly cold choke point between 1500 and 1850. Many Scandinavian villages were consumed by advancing glaciers, whole years went by without so much as a day of summer and seas would freeze over.

This extreme cold significantly curtailed human advancement in many parts of the world. In particular, it caused huge famines, which indirectly contributed to various revolts, wars and it might have even contributed to the rise of witch hunts in Europe, and later in America.

The Garden of Eden May Have Been Real, and May Have Saved Us from Extinction

I’m not on about talking snakes or forbidden fruit here, rest assured, but all stories have an origin that’s somehow grounded in reality, and the Garden of Eden is no exception. 195,000 years ago, us and all our fellow creatures were tight in the grip of the ice age. This was one of the most intense phases of it, and many species didn’t survive it. We might not have done either, if things had gone a little differently.

Most of the early homo-sapiens didn’t survive this, but the few that did were lucky enough to find refuge in what is now South Africa. The narrow strip of land on the southern coast where they settled is now referred to by many scientists as the Garden of Eden, as it was fed by nutritious oceanic currents, brimming with greenery and riddled with caves to hide away from the cold in.

Compounding this theory is the fact that human DNA is far more limited than it should be, suggesting that many other variants of our species didn’t survive this stage of the ice age, and concordantly that we all evolved from the small pocket of humans who made it to Eden. This theory is far from certain, there’s still a lot of debate and the evidence supporting it is still fairly sparse, but it could very well explain a great many things about our evolutionary development. 

Callum Davies

Callum is a film school graduate who is now making a name for himself as a journalist and content writer. His vices include flat whites and 90s hip-hop.