You could think of yourself driving in a mountainous area
with the road circling up the mountain.
An overpowered engine driving much, much too fast,
driving without any headlights.
Cliffs that you're at risk of falling over.
You want, of course, to turn on the headlights,
and that is what science tries to do all the time.
To give us the headlights so we can see what risks we're facing.
Recent discoveries made by scientists
studying the ways in which our planet works
are surely of the greatest importance for all of us.
Their insights are deeply troubling.
Nonetheless, they also give us hope,
because they show us how we can fix things.
One of those who has devoted his life
to studying these globally important problems
comes from Sweden.
What he and his colleagues around the world have discovered
is perhaps the most important scientific insight of our times.
Johan has given us hope.
Hope that there is a way out of this crisis.
And once you too have heard it,
you may never look at the world in the same way again.
This is not about the planet.
This is about us. It is about our future.
We still have a chance.
The window is still open for us to have a future for humanity.
That I think is the beauty of where we are today.
Our understanding of how our planet works
is always advancing.
We can now see more clearly than ever
how life's intricate complexity is essential for our own survival.
But biodiversity is collapsing, and our climate is changing.
Johan Rockström has focused on what keeps our planet stable.
We're the first generation, thanks to science,
to be informed that we may be undermining
the stability and the ability of planet Earth
to support human development as we know it.
This comes from ice core data,
and I think that this is the most important graph we have today.
The graph is a revelation.
It shows global temperature variability
over the past 100,000 years
since the first appearance of modern humans.
We were jumping between plus-minus ten degrees Celsius in a decade.
We had, to put it simple, a rough time.
What's critical is that the temperature stabilized
just 10,000 years ago.
You can just see from the graph that this is a remarkable,
not to say almost miraculously stable, interglacial period.
Geologists have given this period of stability
its own special name.
It's called the Holocene.
The Holocene is remarkable.
It is a warm period where the planet's global mean temperature
varies between just plus-minus one degree Celsius
during the entire period.
…is plus-minus one degree Celsius.
This is what established the modern world as we know it.
The Holocene's stable temperatures gave us a stable planet.
Sea levels stabilized.
For the first time,
we had predictable seasons and reliable weather.
This stability was fundamental.
For the first time, civilization was possible,
and humanity wasted no time in taking advantage.
We domesticated rice, wheat,
teff, maize, sorghum,
on different continents roughly at the same time.
And off we go on the civilizational journey as we know it.
This is the interglacial stage that has enabled us
to develop modern civilizations as we know it.
The Holocene is the only state of the planet we know for certain
can support the modern world as we know it.
Since the dawn of civilization,
we have depended on this stable state of the planet.
A planet with two permanent ice caps,
a cloak of forests,
and an abundance of life.
Throughout the Holocene,
this stable planet has given us food to eat,
water to drink, and clean air to breathe.
But we have just left the Holocene behind.
The exponential rise in human pressures on planet Earth
has now reached a stage
where we have now created our own geological epoch.
Scientists recently declared that the Holocene has ended
and that we are now in the Anthropocene,
the age of humans,
because we now are the primary drivers of change
on planet Earth.
We have converted half the world's habitable land
to grow crops and rear livestock.
We move more sediment and rock than all the Earth's natural processes.
More than half of the ocean is actively fished.
Nine out of ten of us breathe unhealthy air.
And, in a single lifetime,
we have warmed the Earth by more than one degree.
I would say that perhaps the most dire message to humanity
is the following.
So we have, in just 50 years,
managed to push ourselves
outside of a state that we've been in for the past 10,000 years.
Are we at risk of destabilizing the whole planet?
It's just a mind-boggling situation to be in.
For the first time, we have to seriously consider
the risk of destabilizing the entire planet.
Johan's ambition has been to see the big picture.
To draw from a global network of knowledge,
to learn what keeps the entire planet stable.
What are the systems that determine the state of the planet?
And if they are five or if they were 30,
we did not know when we started.
We just open-ended asked the question,
"Can we identify the systems that regulate the state of the planet?"
Those systems have held the planet in its stable state
throughout the Holocene.
As we increase our pressures on Earth,
there is a danger that those systems will start to break down.
That we will break through Earth's boundaries,
causing the stability that we depend on to collapse.
I was absolutely convinced that we wanted
to dig into this challenge of defining planetary boundaries,
and can we identify a quantitative point
beyond which we risk triggering nonlinear changes?