Future Paleontologists Will Understand Modern Humans through Our ‘Technofossils’
Discarded authors Sarah Gabbott and Jan Zalasiewicz, observers of the geological past, look into the future
Klaus Vedfelt/Getty Images
We all wonder about our legacy—what will remain of us when we’re gone? Two paleontologists set out to answer that question for the whole of humankind in a new book that explores how the material abundance of modern life will be preserved in Earth’s geological strata.
This Anthropocene rock layer will catch the eye of anyone digging around millions of years from now, according to Sarah Gabbott and Jan Zalasiewicz, both professors at the University of Leicester in England. Biological fossils will suddenly give way to a strange menagerie of what Gabbott and Zalasiewicz call technofossils: polyester sweaters, QWERTY keyboards, saxophones. These objects, if buried quickly in the right environment (such as a landfill, where they’re often safely entombed in plastic liners), stand a good chance of enduring.
Scientific American talked with Gabbott and Zalasiewicz, authors of the book Discarded: How Technofossils Will Be Our Ultimate Legacy, about the things we’re leaving behind, the ways those items will live on in the environment and the impression that future paleontologists might have of us.
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What do we know right now about the technofossils we’ll leave behind?
GABBOTT: We’re making things that will be more durable than the stuff biology makes. By that reasoning, it’s probably going to last a long time. But [we don’t know] how long and what it’s going to do in that journey from being discarded to being a fossil…. It’s also fascinating to think about some future civilization or aliens visiting Earth. What the hell are they going to make of all this stuff? Those are the two big unknowns.
Let’s start with the first one. How do you study fossilization that hasn’t happened yet?
GABBOTT: We can’t do the experiments because there’s not enough time. So we learn some of these things by looking at analogues in the fossil record. There are these plasticlike polymers that some green algae make [that are] almost identical to polyethylene. And the same green algae have been found in rocks that are 48 million years old—this stuff hasn’t changed. Concrete is another one [that we’ve found analogues for]. It’s really just limestone and shale; we know that lasts forever. A lot of these technofossils, there’s no reason to assume that they’re going to be any different. They’re just going to be incredibly resilient.
You describe our technofossil legacy as a “puzzle” for future paleontologists. Will they be able to solve it?
ZALASIEWICZ: We’re making so many complicated structures that have no [equivalent] in the biological world. So the discoverers will have to realize this is technology, not some kind of biology. Then they have to try to work out what these things were used for. That won’t always be clear.
GABBOTT: What I’m talking to you on now, my mobile phone—these things are just rectangles. They’re going to wonder, what is this? And when I was writing [the book], I hadn’t realized just how ephemeral our digital data can be. These big cloud storage bases, even if they survive, [decoding] that stuff is probably going to be impossible. So we have all this computer stuff…, and I think it’s going to be really hard to work out what it was for. [At least] it’s nice to think that paper actually preserves quite well.
Maybe a fossilized copy of Discarded will become their field guide.
ZALASIEWICZ: It’s a lovely idea. Books themselves [are] at least as fossilizable as your average leaf, and we know you go to the right strata and find fossil leaves by the lorry load. The trouble is the same as when you have many, many fossils piled up on top of each other: you just have a mess. But if you’re patient enough you could actually dissect it—the same, I think, with the pages of any book. It’s a tall order, but you never say anything’s impossible in geology because you get more and more weird and amazing fossils turning up all the time.
What will be the most extraordinary technofossils?
ZALASIEWICZ: We mention these [soccer]-pitch-length [wind turbine] blades, cut up into segments and stacked side by side [after they’ve been decommissioned]. It looks almost surreal. This pattern could preserve, let’s say, on a big cliffside—imagine one of these in a future Grand Canyon. [And] when you think of the bits of a city that are going to be preserved, [it’s] all the bits underground…, the subway systems, the electricity, the drains. Again, one can imagine a cliffside where the underground part of Amsterdam or New Orleans is outlined.
Tomorrow’s marvels are, in many cases, today’s pollution. How do you think about that?
ZALASIEWICZ: There really is a connection between the far future and the uncomfortable, dangerous, toxic present. We put stuff into a landfill because we have a problem. We put it into a hole—problem solved. But of course, that landfill site is subject to all the processes that affect any fossil. If it’s buried, it can easily be exhumed [by geological processes] and go back into the surface environment at intervals of tens of millions of years.
GABBOTT: Because this stuff is going to last a long time, because this stuff is polluting now, we really need to start thinking: Do I need another pair of sunglasses? Do I need another mobile phone?
Speaking of which, I know from a vague passage in the book that one of you still has a flip phone.
ZALASIEWICZ: [Holds up some primitive, dimly familiar device] Me. I never quite caught up. My son is very tech-savvy, so perhaps he will guide me into this strange new world. But I still survive with it. It still gives me enough.
What story will our technofossils tell about us?
GABBOTT: They will tell that we were a complex society, that we were technologically able, intelligent. But also they will tell of a species that was profligate, that made things in vast numbers…, using up resources without knowing the downstream consequences.
ZALASIEWICZ: The fact that all of this is being done while there is evidence of increasing environmental perturbation, I think, will strike them. The better angels and the worse angels of our nature will both be fairly obvious.