[INTRO MUSIC] [MUSIC] A curious group of explorers stumble upon a planet.

Their sensors pick up an interesting chemical profile.

Large amounts of water.

Temperatures moderate enough to keep most of it liquid.

An atmosphere containing higher than expected levels of oxygen.

The land is oddly green.

Its an abnormal place, worth investigating.

This planets name is Earth.

These explorers will find an Earth teeming with life, but in our story, Homo sapiens is not among them.

Maybe weve moved on.

Maybe weve died out.

But this planet is no longer ours.

The strange plants and animals, although our explorers wouldnt call them that, can only tell how this planet IS, not how it WAS But they have knowledge of geology, they understand the strata of rocky planets.

And where they examine layers of rock, stacked one on top of another, they will be able to piece together our story.

Consider what we know about the dinosaurs.

They existed for more than a hundred million years, yet we have only uncovered a few thousand complete remains.

Our species has been around just a fraction of that time.

But despite this relatively short existence, weve left a huge mark, and today, scientists are more certain than ever: weve changed Earth to such an extent that geologists digging in the distant future would classify this as a totally new epoch.

The Anthropocene.

But when would it begin?

What would they find there?

The rise of farming, countless empires, most of human historys timespan in fact, would be almost invisible in the rock.

But theyd notice us.

During the Industrial Revolution our species numbered 1 billion for the first time, accelerating until around 1950, when population growth and human consumption explode.

The Great Acceleration.

This era of unprecedented economic change and consumption would be unmistakable in the rocks.

ns materials never before seen on Earth.

I want to say one word to you.

Just one word: Plastics.

Every year, we pump out a mass of plastic equal to the weight of all humans on Earth.

And not just plastics, also glass and bricks.

Although theyre made from raw minerals, theyre modified by heat into forms both long-lasting and notably organized.

Consider aluminum, it was essentially unknown in its pure elemental form before the 19th century, yet since 1950 weve produced enough for every human alive to make a stack of cans half a kilometer high.

Enough concrete has been produced to pave all of earth, and half of that since just 1995.

All of this stuff would mark the most new minerals created since oxygen first built up in our atmosphere, 2.4 billion years before you are watching this video.

And beyond these raw materials would be traces of the things weve made with them.

Our technofossils.

From planes and phones to paper clips and lost ballpoint pens, countless confusing And should these future explorers be versed in chemistry, theyd find metals and rare-earth elements spread worldwide, and strangely missing from the lower layers where we dug them up.

A few, like platinum, rhodium, and palladium would be strangely concentrated along strands of a strange web, ejected long ago by catalytic converters attached to cars on our roads.

Theyd see huge spikes in nitrogen and phosphorous from fertilizer production.

Were they to find ice on this future Earth, ice cores would show sudden spikes in methane and carbon dioxide, like nothing seen in the 800,000 years previous.

If they found fossils, they would see many species go from local concentrations in older layers to sudden global spread, marks of our domestic animals, plants, and invasive species.

And like we have witnessed in our own time, these future explorers would see a spike in the number of species that suddenly disappear from the fossil record: A Mass Extinction Event.

Weve talked about this at length in a previous video and we dont yet kn ow how bBuadt iast twihelly gdeetco.de d the dawn of the Anthropocene, there would be one mark clearer than all the others, tracing back to a single day in Earths history.

July 16, 1945 the detonation of the first atomic bomb.

Rare radioactive elements like 239Pu and its decay products would leave a chemical signature that our future explorers could not help but notice, although they might not be able to explain its origins.

It makes you wonder, what would they think of us?

What picture of our species, of our culture, would they connect from these dots?

Whoever it may be that one day examines the Anthropocene, the layer of Earth that will represent us, remember that we control what it holds, and how much time it will represent.

Stay curious.