It’s the only place in the entire universe we know for sure can support life. It’s ideal for humans,
but also the billions of other creatures that live here, so it’s difficult to imagine
anything forcing us to give it all up. But what if that’s exactly what we had to do?
This is Unveiled, and today we’re answering the extraordinary question;
what if humanity had to abandon Earth?
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While we’ve had our eyes on the stars for centuries now, we still haven’t built colonies
or settlements beyond Earth’s atmosphere. The closest thing we have are space stations,
and the largest one ever built, the ISS, only comfortably supports six astronauts at
once – and never more than thirteen. One reason for this is that as much as we all love space,
it isn’t at all a welcoming place. In fact, it’s dangerous. And, then,
there isn’t much of a clear financial incentive for us to venture into the great abyss, either…
which is why it’s taking such a long time to even tentatively begin to travel the solar system.
Nevertheless, if something happened to make Earth completely uninhabitable - some kind of global,
unparalleled disaster - then we’d have no choice but to take off. If we didn’t, the human species
(and maybe life in general) would die. Such a world-ending cataclysm could be man-made, the
result of a nuclear war, perhaps. Or it could be a natural disaster, like a super-volcanic eruption
or a giant asteroid impact. But, even if we were able to survive all of those possibilities for
literally millions of years, then in just a few billion years’ time the sun is scheduled to expand
into a red giant and either consume Earth as it does so, or else make it far too hot for anything
to carry on living here. All of which means that, although this is a hypothetical question,
if humans live long enough then it is also one that they will have to answer!
So where, exactly, would we be able to go when the worst happens? And what if it happens much sooner
than we’d care to anticipate? In the long-term, our best bet would be to head to an alien planet
that’s both close and Earth-like. Sounds simple, but this already poses an almighty challenge
because no other bodies in the solar system really match that criteria. Mars, for example,
is so often pitched as our species’ next new home. And it is relatively close compared to
most of everything else in space… but it would still be largely, almost totally inhospitable
in its natural state. The technology needed to terraform Mars needs to be developed,
then, but we’re still very far away from anything on a mass scale. So, in practice,
even if we had the know-how to get there (which we don’t at the moment), moving to
Mars means living in cold, arid, lonely deserts, in tiny, severely limited, artificial habitats.
This might be fine for a select few of the bravest and hardiest astronauts, but it’s definitely not
for everyone… to the point that Mars (as it is) probably doesn’t represent much of an upgrade
compared to our hypothetically inhospitable Earth. Meaning we might as well stay put.
Of course, in time, that could all change. We could reach Mars in the next decade or two, slowly
begin to eke out a human presence there, and when the time came to evacuate Earth, we might’ve
already built for ourselves the perfect cosmic bolthole. Or we might choose to look the other way
and try Venus where, as we found in another video, we could theoretically carve out an existence in
the Venusian clouds. Naturally, though, if we were evacuating Earth due to the sun’s expansion,
then Venus wouldn’t be the way to go! Elsewhere, but even further afield, Titan and
Europa, the oceanic moons of Saturn and Jupiter, are usually billed as our best bets. Again,
though, it’s not as though getting to either (or surviving on either) would be easy or even
possible unless we were to make gigantic leaps forward in science and technology.
The cold, hard truth is that if we were for some reason forced to evacuate Earth tomorrow,
nobody - not even the richest and most privileged among us - would have anywhere to go. Right now,
all we really have is ideas on where we could go, without any means of getting there.
Looking on the bright side, though, it remains highly unlikely that we actually would all need
to evacuate Earth tomorrow, or next week, or even by this time next year. Something truly terrible
and devastating could happen, yes, but we can with reasonable safety assume that it won’t.
Which means we can look at alternative evacuation plans for further into the future, too. Ones that
don’t necessarily involve the colonisation of other, probably dangerous planets. Perhaps,
for example, we should already be trying to build our own habitats,
perfectly designing them to support human life. We could build orbital cities and space stations.
Or we could build generation ships, capable of supporting huge numbers of people in the
vacuum of space indefinitely – until they come across a genuinely suitable, actually survivable,
Earth-like exoplanet, somewhere beyond the Oort Cloud and outside of the solar system.
The private space firm Blue Origin is reportedly already planning on building orbital cities,
using blueprints first drawn up in the 1970s by physicist Gerard K. O’Neill… so,
many see projects like these as far more realistic compared to settling on alien worlds.
While still incredibly far off, space cities and generation ships also have the advantage
of not needing to be so place specific, or time sensitive. A working generation ship might drift
through space for, well, generations, constantly tweaking its route in search of a new home,
but in the meantime ensuring that humanity as a species does at least continue to exist. Of
course, the big problem is how exactly would we ever build something like this? In theory,
to give ourselves the best chance, we’d need to construct it already off the ground,
in low-Earth orbit - much like we’ve already done for the International Space Station. Then,
for either a space city or a generation ship, we’d need to ferry potentially billions of people from
the Earth’s surface up into it. And we’d need to do all of that between now and whenever Earth were
to become inhospitable in the first place. It’s not exactly a simple task, now is it.
Even much smaller scale evacuations, just here on Earth, are already extremely difficult to
organise. And that’s despite us having planes, helicopters, boats and all kinds of terrestrial
vehicle available to move lots of people very quickly. Now imagine the levels of organisation
needed to ship literally everyone not just to another part of the planet, but away from the
planet entirely. Our boats, planes and trains could move us to our pickup points, but after
that they’d be pretty much useless! As a result, we’d likely see massive social division when it
came to deciding who got on the rockets first. Today, there are more than seven-and-a-half
billion people living on Earth, but how many of those have so far been into space?
It’s less than six hundred! So, there’s really no blueprint for how this would go.
Countries with large and successful space agencies would immediately be at an advantage.
But that doesn’t necessarily mean that even every American citizen or Russian national would find it
easy getting a ticket off of Earth, just thanks to the existence of NASA and Roscosmos. What’s
more likely is that various high-ranking figures and trained specialists - including astronauts,
lead scientists and politicians - would be among the first off of the ground. And, for as long as
spaces were limited, the rest of the earliest seats would probably go to the highest bidder,
or else be divided up and handed out via some kind of lottery. Needless to say, while all of that was
going on, life down here, on doomed Planet Earth, could turn into panic-ridden chaos.
That said, even if the Apocalypse really was nigh, it’s not as though everyone would want to leave.
History shows us how human beings often refuse to abandon their homes, even in times of great
danger. Millions of people currently live within the vicinity of potentially deadly volcanoes,
for example - such as around Mount Vesuvius, in Italy. And, then, there are those like the
samosely (or self-settlers), a small community who, after the Chernobyl Disaster in 1986,
refused to evacuate the radioactive Exclusion Zone. In the event of a truly global disaster,
then, there’d also be many - potentially millions - of people who just wouldn’t want to go.
No matter the risk. And so, while everyone else clambers for seats on spaceships, they’d
be preparing to struggle against whatever it was that the rest of humanity was running away from.
Of course, although in this video we’ve focussed on the hypothetical plight of Earth-abandoning
humans, this scenario poses plenty of other problems, too. Like, what about the rest
of life on Earth? What happens to all of the plants and animals and bacteria and microbes?
Keep your eyes peeled for follow-up episodes, for more about animals in space.
And in the meantime, let’s try to enjoy the planet we have,
and look after it. Because that’s what would happen if humanity had to abandon Earth.
What do you think? Is there anything we missed? Let us know in the comments, check out these other
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