In January of 1995, Russia detected
a nuclear missile headed its way.
The alert went all the way
to the president,
who was deciding whether to strike back
when another system contradicted
the initial warning.
What they thought was the first missile
in a massive attack
was actually a research rocket
studying the Northern Lights.
This incident happened
after the end of the Cold War,
but was nevertheless one of the closest
calls we’ve had
to igniting a global nuclear war.
With the invention of the atomic bomb,
humanity gained the power to destroy
itself for the first time in our history.
Since then, our existential risk—
risk of either extinction
or the unrecoverable collapse
of human civilization—
has steadily increased.
It’s well within our power
to reduce this risk,
but in order to do so,
we have to understand which
of our activities
pose existential threats now,
and which might in the future.
So far, our species has survived
2,000 centuries,
each with some extinction risk
from natural causes—
asteroid impacts, supervolcanoes,
and the like.
Assessing existential risk is
an inherently uncertain business
because usually when we try to figure out
how likely something is,
we check how often it's happened before.
But the complete destruction of humanity
has never happened before.
While there’s no perfect method to
determine our risk from natural threats,
experts estimate it’s about
1 in 10,000 per century.
Nuclear weapons were our first
addition to that baseline.
While there are many risks associated
with nuclear weapons,
the existential risk comes
from the possibility
of a global nuclear war that leads
to a nuclear winter,
where soot from burning cities
blocks out the sun for years,
causing the crops that humanity
depends on to fail.
We haven't had a nuclear war yet,
but our track record is too short to tell
if they’re inherently unlikely
or we’ve simply been lucky.
We also can’t say for sure
whether a global nuclear war
would cause a nuclear winter so severe
it would pose an existential threat
to humanity.
The next major addition to our existential
risk was climate change.
Like nuclear war,
climate change could result
in a lot of terrible scenarios
that we should be working hard to avoid,
but that would stop short of causing
extinction or unrecoverable collapse.
We expect a few degrees
Celsius of warming,
but can’t yet completely
rule out 6 or even 10 degrees,
which would cause a calamity of possibly
unprecedented proportions.
Even in this worst-case scenario,
it’s not clear whether warming would pose
a direct existential risk,
but the disruption it would cause
would likely make us more vulnerable
to other existential risks.
The greatest risks may come
from technologies that are still emerging.
Take engineered pandemics.
The biggest catastrophes in human history
have been from pandemics.
And biotechnology is enabling
us to modify and create germs
that could be much more deadly
than naturally occurring ones.
Such germs could cause pandemics
through biowarfare and research accidents.
Decreased costs of genome sequencing
and modification,
along with increased availability
of potentially dangerous information
like the published genomes
of deadly viruses,
also increase the number of people
and groups
who could potentially create
such pathogens.
Another concern is unaligned AI.
Most AI researchers think this will be
the century
where we develop artificial intelligence
that surpasses human abilities
across the board.
If we cede this advantage, we place
our future in the hands
of the systems we create.
Even if created solely with humanity’s
best interests in mind,
superintelligent AI could pose
an existential risk
if it isn’t perfectly aligned
with human values—
a task scientists are finding
extremely difficult.
Based on what we know at this point,
some experts estimate the anthropogenic
existential risk
is more than 100 times higher
than the background rate of natural risk.
But these odds depend heavily
on human choices.
Because most of the risk is from human
action, and it’s within human control.
If we treat safeguarding humanity's future
as the defining issue of our time,
we can reduce this risk.
Whether humanity fulfils its potential—
or not—
is in our hands.