If another advanced civilization lived on Earth before us, would we know?

By Ruth Behrens · Reporting from Newell, Iowa · July 26, 2026

The men who wrote this paper—Frank and Schmidt—are brilliant minds, I’ll give them that.

The Trouble with Looking Back at Mega-Civilizations

The men who wrote this paper—Frank and Schmidt—are brilliant minds, I’ll give them that. But when they get out on a soapbox about finding the ghost of an ancient industrial civilization in the rock record, it feels like a distraction. They are asking if we can detect the "planetary footprint" of some long-gone species, maybe even ones that could compose poetry, as zmescience.com reports. It’s a thought experiment built on the idea that every time humanity gets big enough to burn fossil fuels and leave a chemical signature, it'll be recorded forever in the strata. They point to things like unusual isotope ratios or massive carbon spikes—the kind of changes seen during the Paleocene-Eocene Thermal Maximum 55 million years ago.

But here’s what I keep thinking: who is doing the looking? And why are we so obsessed with civilizations that existed when the planet was still figuring out how to breathe? No verified historical parallel survived fact-checking for this story. The science, as scientificamerican.com laid it out in 2018, suggests that after a couple of million years, any physical reminder of your civilization has vanished; you have to search for abstract chemical anomalies instead.

Where the Real Fingerprints Are Left Today

The whole premise—that we might be able to tell if an industrial society existed millions of years ago—is fascinating enough for a university seminar, but it misses the point entirely. It’s all about the signal. The authors themselves note that "the longer human civilization lasts, the larger the signal one would expect in the record."

We are talking about globalized effects: massive carbon emissions and warming oceans. When I read through the reporting on this topic, my mind keeps snapping back to something far more immediate than finding a forgotten plastic shard deep underground. The real fingerprint is what we’re doing right now. It's the constant pressure on Main Street; it’s the fact that the local school board has to dip into reserves just to keep the lights on. Those are chemical signatures, too—signatures of economic stress and unsustainable practices.

The Ground Truth vs. The Deep Time Theory

The biggest mistake in this whole exercise is treating human activity as a singular, clean event separated by millions of years from everything else. They want us to look for global traces left by some ancient machine-wielding race, but they ignore the most durable and undeniable evidence: the people who have to live on the ground right now.

The theory itself—the Silurian hypothesis—is wonderful and deeply thought-provoking, as cnn.com reported, but it is fundamentally academic. It lets us worry about ghosts in the rock instead of dealing with the fact that our own local economies are eroding faster than any sediment can accumulate. We need to be looking at the basis charts for the county feed store, not the carbon isotope ratios of ancient seas.

While science is always right to ask "what if," this theory distracts us from the only verifiable crisis: the fact that our current civilization—our local one—is already leaving an undeniable, measurable footprint on a planet struggling to hold itself together. We should be worrying about what we leave behind in the next fifty years, not what might have been left 50 million.

If another advanced civilization lived on Earth before us, would we know?

The Trouble with Looking Back at Mega-Civilizations

Where the Real Fingerprints Are Left Today

The Ground Truth vs. The Deep Time Theory

Sources