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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. It’s an abnormal place, worth investigating.

This planet’s name… is Earth.

These explorers will find an Earth teeming with life, but in our story, Homo sapiens

is not among them. Maybe we’ve moved on. Maybe we’ve died

out. But this planet is no longer ours. The strange plants and animals, although our

explorers wouldn’t 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,

we’ve left a huge mark, and today, scientists are more certain than ever: we’ve 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 history’s timespan in fact, would

be almost invisible in the rock. But they’d 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.

Our waste contains 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 they’re made from raw minerals,

they’re 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 we’ve 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 we’ve made with them. Our

technofossils. From planes and phones to paper clips and lost ballpoint pens, countless confusing

traces of our time.

And should these future explorers be versed in chemistry, they’d 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.

They’d 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. We’ve talked about this at length in a previous video… and we don’t yet

know how bad it will get.

But as they decoded the dawn of the Anthropocene, there would be one mark clearer than all the

others, tracing back to a single day in Earth’s 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.