Did an extinct civilization pre-date mankind on Earth? Scientists say it would be ‘easy to miss’ the signs of an industrial society like our own even if it were buried right under our noses
- Experts wondered if it would be possible to find signs of a short-lived society
- They set out to discover what kind of evidence could conceivably still exist
- The presence of plastics in the ocean and use of fertiliser could be indicators
- Their thinking could also aide in the search for alien life on other planets
It may sound more like a conspiracy theory than a subject for a scientific inquiry but scientists have posed a fascinating question about the timeline of Earth’s inhabitants: was another industrial civilisation on Earth before humans?
In a new study, a climatologist and a professor of astrophysics teamed up to explore whether an extinct pre-human species could have caused global warming 56 million years ago.
Geological records reveal a period of dramatic change buried deep in the planet’s history known as the Paleocene-Eocene Thermal Maximum (PETM).
While there is little question about whether this spike was the result of natural forces – the researchers note it was ‘almost certainly not’ caused by an ancient industrial civilisation – the study offers insight on the impacts our own society could leave on this planet millions of years down the line.
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It may sound more like a conspiracy theory than a subject for a scientific inquiry but scientists have posed a fascinating question about the timeline of Earth’s inhabitants: was another industrial civilisation on Earth before humans? File photo
To investigate this idea, the pair set out to discover what kind of evidence could conceivably still exist to demonstrate this event was caused by a pre-human industrial society.
In doing so, the pair considered what evidence from our own culture would be left behind for future civilisations to uncover after the passage of aeons.
Their thinking could have widespread implications for our understanding of how best to look for alien life on other planets.
Professor Adam Frank, of the University of Rochester reports their findings in an in-depth article for The Atlantic.
The astronomer’s initial interest in the subject was sparked after a conversation with fellow physicist Gavin Schmidt, director of Nasa’s Goddard Institute for Space Studies (GISS) in New York.
Professor Frank was hoping to solve the question of whether any industrial civilisation that rises on any planet in the universe will trigger a shift in their homeworld’s climate.
Upon hearing about his research, Dr Schmidt questioned his assumption that humanity is the only time a civilisation has arisen that is capable of affecting the Earth’s climate.
Writing in The Atlantic, Professor Frank said: ‘There is a conundrum here. If an earlier species’s industrial activity is short-lived, we might not be able to easily see it.
In a new study, a climatologist and a professor of astrophysics teamed up to explore the far-fetched idea. They examined the notion that a period of global warming 56 million years ago may well have been made (stock image)
‘The PETM’s spikes mostly show us the Earth’s timescales for responding to whatever caused it, not necessarily the timescale of the cause.
‘So it might take both dedicated and novel detection methods to find evidence of a truly short-lived event in ancient sediments. In other words, if you’re not explicitly looking for it, you might not see it.’
Evidence of ancient industrial civilisations might include the presence of plastics in the ocean, as well as fossil fuel use and the distribution of fertiliser in agriculture.
Fossils and other remains are likely to have blown away with the sands of time.
While they were unable to establish the presence of any such proof, their thought experiment lead to some interesting ideas – particularly when it comes to other planets.
It suggests the possibility of a string of alien cultures on a single planet which are literally fuelled by the bodies of the predecessors.
Evidence of ancient industrial civilisation might include the presence of plastics in the ocean, as well as fossil fuel use and the distribution of fertiliser in agriculture. Fossils and other bodily remains are likely to have blown away with the sands of time (stock image)
Professor Frank proposes that civilisations might in their collapse trigger the conditions needed for oil, gas and other natural reserves to be built up.
Future civilisations could then use these to build up to their own industrial periods, before collapsing and starting the cycle again.
He added: ‘Our work also opened up the speculative possibility that some planets might have fossil-fuel-driven cycles of civilization building and collapse.
‘If a civilization uses fossil fuels, the climate change they trigger can lead to a large decrease in ocean oxygen levels.
‘These low oxygen levels (called ocean anoxia) help trigger the conditions needed for making fossil fuels like oil and coal in the first place. In this way, a civilization and its demise might sow the seed for new civilizations in the future.’
The full findings of the study were published in the International Journal of Astrobiolog.