What Will Humans Leave Behind? Plastic Stones, Cities, And Lots And Lots Of Trash

As humans, we’re altering the world on a huge scale. Say hello to technofossils and the Anthropocene.

Humans constantly change the environment around them. From cave drawings to huge cities, to heaping piles of trash, this tendency has resulted in what some call a new geological era known as the Anthropocene, age of man.

In essence, humans have become a major geological force

  • plastic and concrete that
  • CO2 and methane in the atmosphere
  • isotopes from nuclear weapon tests in the 1950’s and 60’s

The change has been particularly acute since the middle of the twentieth century, according to some experts.


When strange stones comprised of volcanic ash, sand, shells, and plastic were discovered by oceanographer Charles Moore on the shores of Hawaii’s Kamilo Beach in 2006, their significance was not realized until 2012, when earth scientist Patricia Corcoran investigated the objects further.

The findings were published (pdf) in GSA Today, which christened the stones plastiglomerates, multi-composite material formed from bonfires on beaches.

Researchers collected and studied 205 from Kamilo Beach, and believe more to exist on polluted beaches across the world.

Screen Shot 2014-06-17 at 9.05.13 PM
From GSA Today.

Figure A: Material composing the sampled plastiglomerate: B—basalt clasts; C—coral fragments; P—plastic; S—sand and sand-size shelly fragments; W—woody debris.

Figure B: Pie diagram showing the relative abundance of different plastic products in plastiglomerate.

This is only the latest of many tangible changes humans have either consciously or unconsciously to the planet.


The plastiglomerate has been called a technofossil: the preservable remains of the technosphere, the part of the earth influenced by humans that may last as future fossils for millions of years.

Screenshot from YouTube.com.

Given the state of marine debris today, which fills ocean vortexes and the bellies of albatrosses, it’s hardly surprising that plastic has merged with nature in a way not limited to the shores of Hawaii.

According to research published in The Anthropocene Review, a new journal from SAGE, the fossil impacts humans have left on nature is unprecedented, with diversity and rate of evolution creating a trace greater than any in Earth’s over four-billion-year-long history.

Where most animals leave traces limited to bones and footprints, humans will leave everything we build and manufacture (cities, roads, cell phones, toothbrushes, etc) along with the more unintended ones, like plasiglomerates and space debris.

Photo courtesy of Keven Davis via Flickr.

An altered world

On a larger level, it isn’t just fossils that will mark the age. Plastiglomerates are evidence of a structural change in geology — but we’ve also altered the atmosphere, hydrosphere, cryosphere, and biosphere significantly — in short, our entire climate.

Not to mention the trillions of pounds of garbage generated annually – which America makes a third of. Some of it ends up in plastiglomerates, but most of it ends up in landfills.

All in all, 80% of the Earth’s surface has been marked by human activity. The depth and scale of it is so huge, it’s said to be “on a scale comparable with some of the major events of the ancient past.”

Though the Anthropocene is not yet an official epoch, it may be added to the permanent geological timescale in 2016.

Updated. Cover photo courtesy of Doc Searls via Flickr.

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Jennifer Markert