For a variety of reasons, the climate is at the forefront of all our minds in
the twenty-first century. There’s a wealth of information and analysis for us to draw upon,
as we try to make sense of what the future has in store. Much can be learnt by looking back in time,
as well, though… and revisiting past eras of notable or unusual atmospheric conditions.
So, this is Unveiled, and today we’re answering the extraordinary question;
What’s it really like to live in an ice age?
Do you need the big questions answered? Are you constantly curious? Then why not subscribe to
Unveiled for more clips like this one? And ring the bell for more thought-provoking content!
Despite its widespread acceptance now, the theory of ice ages
wasn’t always popular. One of the more common beliefs before the nineteenth century,
for example, was that ancient creatures and environments had been killed off
by a massive flood... but we now know differently. Since the mid-1800s,
science has explained how Earth’s history actually played out, via breakthrough experiments on rocks
and minerals that were found to have been left behind by glaciers in the distant past. However,
fast forward to today, and still relatively little is known about how these global winters start.
Broadly speaking, we have Earth’s orbit and plate tectonics to consider. Our planet’s position,
its axial tilt, and any of the numerous “wobbles” that it can experience as it hurtles through space
are what generally cause the summers and winters to get warmer… or, in this case, colder. And,
at some points, a change in these fundamental conditions - even a small change - can allow
for ice to build up. This is at the heart of what are known as Milankovitch Cycles,
named after the Serbian astrophysicist Milutin Milankovic, who discovered the link in the early
twentieth century. Combine this with the fact that Earth’s land masses never stay in one place,
thanks to tectonic movement, which also has an effect on oceans and ocean currents,
and the atmospheric balance on Earth can break, meaning an ice age can set in.
There are two main phases to an ice age: the glacial and interglacial periods. You’ve probably
heard it said before that we’re technically in the middle of an ice age right now, and that’s because
we’re in an interglacial period of an era known as the Pleistocene Ice Age. In an interglacial
period, temperatures become much warmer… but we know that we’re not completely ice age-free
right now, because regions such as Antarctica and Greenland still host vast ice sheets - at least,
for the time being. These sheets (although smaller than they once were) are still present from
the last glacial period on Earth, and under usual conditions we’d expect them to return
in the future. However, in the modern world, we have human induced climate change to add into the
equation, as well. The effects of which have led many analysts to worry that the cycle of ice ages
might be permanently broken. That, if another glacial period does come,
it could be delayed by thousands of years. To date there have been five main ice ages in
Earth’s history, with the first one reaching back as far as around 2.4 billion years ago… to the
most recent, which started just 2.6 million years ago. But there have been many minor ice ages, too,
dotted between the bigger, broader events. And records show that there have been dozens in the
last million years alone, with the last ice age of all peaking around 20,000 years ago.
The glacial period of an ice age is so called because during it massive
ice sheets and glaciers form and cover up much of the planet. During the last glacial period, which
ended around 12,000 years ago, huge parts of North America and Canada were completely covered in ice,
as well as much of northern Europe. Not only did these ice sheets cover the areas of entire modern
day countries and continents, though, but they were also more than two miles thick in places.
We can see, then, that if you were living in an ice age, there’d be large parts of the planet
effectively off limits… and, in general, the closer to the equator the better.
The amount of habitable land on an ice age Earth is, then, severely limited. This wasn’t a major
problem for the early humans who lived through the last glacial period all those years ago… but
it would be an issue in today’s world, with the current (dramatically increased) global
population. However, the ice sheets aren’t the only change. Because the ice comes from the
oceans, the sea levels in an ice age are lower… and were hundreds of feet lower in some parts,
during the last one. Naturally, this means that land is revealed during an ice age that may’ve
been long been submerged below water before. Which could mean anything from the appearance of fresh
mountain ranges… to new land bridges connecting dry land that wasn’t previously linked.
The severity of the cold itself can vary, but the global temperature during an ice age drops
on average by around ten degrees Fahrenheit. On a global scale, that’s an extreme change… so
living in an ice age would require having to deal with it. The most severe ice age that Earth
has ever seen is known as the Cryogenian Period, when it’s thought to have been
so cold that ice covered the entire planet in a phenomenon known as a Snowball Earth. Fortunately,
humans weren't yet around at this time, because surviving it for near enough any complex life form
would have been almost impossible. Because of the temperatures at play, farming
and agriculture - crucial for modern humans - would be severely limited in an ice age. Many of
the plants and animals that we regularly consume now wouldn’t be able to withstand the cold, while
the dryness that ice ages also bring (resulting in polar deserts) would increase the difficulty.
As a result, life during a glacial period would require a different and limited diet. In the past,
meat came mainly from larger animals that could resist the cold, including bison and wolves,
with the coats of these creatures also proving useful. With our current tools and technology
hunting even the biggest animals around would be relatively easy… but hunters in ice ages past
weren’t quite so well equipped, and often fought animals up close, no matter the danger involved.
Ice age homes would also pose vastly different problems to those we face today.
Shelter would need to be somewhere that’s as shielded from the elements as possible,
which sometimes meant caves. It’s thought that ice age humans built tent-like structures too,
though, sometimes again using animal skins, with large fires blazing in the middle of them.
These homes also had the advantage of being easy to take with you whilst traveling,
and much of the travel was done away from the thickest ice sheets,
and in large packs. It's thought this tendency to continually move, and do so in groups, played a
large part in our continued survival to today. And cooperation within the group was vital.
Life in an ice age is also a disciplined existence. Hunting was more successful
if the attacks were planned ahead; it was rarely wise to stray too far from others;
adequate clothing and sleeping arrangements to protect against the cold were essential,
or else frostbite would quickly set in. While most of your time would’ve been spent hunting,
gathering, or migrating to new areas in search of food or a warmer climate, we know that there
were some more recreational pursuits, too - including painting and the telling of stories.
If, then, by some bizarre miracle, an ice age at the height of its glacial period
were to descend suddenly on Earth tomorrow, our experience of it would of course be made
significantly easier by modern technology. But there are certainly ways that we’d struggle,
as well. Our ancient ancestors had the knowhow to make fires by hand, craft tools, gather resources,
hunt food, move with the seasons, and carry their own homes… all skills that, perhaps,
far fewer of us have today. It’s likely that if the very worst conditions did set in tomorrow,
many would perish… and life expectancy, creeping up and up in recent times as it has done,
would fall back dramatically. But remember, technically speaking,
we are in the middle of an ice age right now… it’s just not as though ours is in
full swing at present. The interglacial period rolls on, and time will tell quite how our climate
unfolds in the future. But until then… that’s what it’s really like to live in an ice age.
What do you think? Is there anything we missed? Let us know in the comments, check out these other
clips from Unveiled, and make sure you subscribe and ring the bell for our latest content.