After Us…. Deep Time: Part 1

A thought-provoking article in Scientific American last month posed the question what would the world be like if the human race were to disappear? The article, based on a book by Alan Weisman “The World Without Us”, doesn’t look for a reason why humanity might vanish – one can propose any number of more or less likely eventualities that might produce that result. Instead it concentrates on the effects our presence and our subsequent departure would have in shaping the physical and biological fabric of the planet.

Weisman has travelled widely to study zones that humanity has already retreated from. These are few and far between, a fact that is indicative of the rapacious spread of our species across the planet. Examples include the Chernobyl area which after two decades provides perhaps the clearest example of short term changes on a post-human environment. The DMZ (Demilitarised Zone) between North and South Korea is another such example. A thin ribbon barely 2.5 miles wide and 150 miles long separates the two states, and this has become the most unlikely of wildlife sanctuaries. Even in Europe there remain pockets of the original proto-forest which human expansion reworked into agricultural land.

The effects Weisman records are fascinating. Those at the nearer end of the time-scale perhaps a little more so because here the rundown of technological civilisation, the unpinning of each of the interlocking elements that comprise our remarkable yet incredibly fragile and tenuous shield against an essentially inhospitable environment, is easily comprehensible. As Weisman says:

“I had a fascinating time talking to engineers and maintenance people in New York City about what it takes to hold off nature…The name ‘Manhattan’ comes from an Indian term referring to hills. It used to be a very hilly island. Of course, the region was eventually flattened to have a grid of streets imposed on it. Around those hills there used to flow about 40 different streams, and there were numerous springs all over Manhattan island. What happened to all that water? There’s still just as much rainfall as ever on Manhattan, but the water has now been suppressed. It’s underground. Some of it runs through the sewage system, but a sewage system is never as efficient as nature in wicking away water. So there is a lot of groundwater rushing around underneath, trying to get out. Even on a clear, sunny day, the people who keep the subway going have to pump 13 million gallons of water away. Otherwise the tunnels will start to flood.”

That it would take only 2 days for the subway to flood indicates how contemporary civilisation is a mutable and organic construct which must fend constantly to maintain itself.

Within 7 days nuclear power plants would be ablaze. Within 2 years roads would have cracked open and within 10 years buildings would be pitted and scarred from the elements. As soon as 20 years after the disappearance of humanity the buried waterways would reassert themselves overground and Manhatten would become many islands with rivers taking on the rectangular grid pattern of the city. At the end of a 100 years almost all roofs would have collapsed. Within 300 years suspension bridges would have collapses. WIthin 5,000 years nuclear weapons would have corroded releasing radioactive plutonium. Around 15,000 years from now the remains of our cities would be ground down by glaciation. By 100,000 years CO2 levels would finally return to preindustrial levels.

Some artifacts would survive into deep time… Even after 10 million years bronze sculptures would survive, largely intact. There is something remarkable about the thought that “…some ordinary items would resist decay for an extraordinarily long time. Stainless-steel pots, for example, could last for millennia, especially if they were buried in the weed-covered mounds that used to be our kitchens. And certain common plastics might remain intact for hundreds of thousands of years; they would not break down until microbes evolved the ability to consume them”.

These are the most ordinary of our artifacts, used in our general material culture. Yet they would outlast our buildings, our vehicles and any other of the ‘high’ achievements of our technology, becoming embedded within near-geological time spans. I have noted problematic aspects of the concept of ‘ephemera’ before in relation to material culture. In this context all is ephemeral.

The point is made that most of the more durable items are those that post-date the Second World War. A rich trove for any species that made the jump to sentience after us. And there would be a number of contenders. Primates have a head start above other species and some suggest that baboons might well fill the niche we left behind. Interesting, particularly since many of the resources humanity has benefited from would be close to exhaustion providing a perhaps insurmountable obstacle to any subsequent technological civilisation.

Ironically aspects of our visual culture would survive all other traces of our species, even the actual death of the Earth and the solar system, in the form of television broadcasts travelling through space. Fragile, yet enduring, patterns of light and sound would be our final legacy.

Weisman takes a philosophical view of all this…

“I raise the question, Wouldn’t it be a sad loss if humanity was extirpated from the planet? What about our greatest acts of art and expression? Our most beautiful sculpture? Our finest architecture? Will there be any signs of us at all that would indicate that we were here at one point? This is the second reaction that I always get from people. At first they think, This world would be beautiful without us. But then they think, Wouldn’t it be sad not to have us here? And I don’t think it’s necessary for us to all disappear for the earth to come back to a healthier state.”

But the thought struck me that in a way any future is utterly unknowable. We all of us are trapped within a very limited time frame. Our lives are miniscule in the context of historical and geological timeframes. Indeed it is striking how we act in the present as if there is a personal future for us that somehow extends beyond any plausible reality.

In a way this is a sort of shared delusion, and this book perhaps feeds into a shared sense of wonder about the nature of the world about us after we have gone. We won’t be there. But nonetheless we remain enormously curious about it. And it is remarkably similar to the process by which we attempt to map and read the past so that it is possible to place some order and meaning upon it. Yet this book attempts to map a possible future in order to better read the present.

I’d suggest that it might make a worthy point of reference for those of us interested in visual or material culture so that we can better appreciate just how fleeting those elements are that shape both our past and present.

Ciarán Swan

[For a short video clip on “Your House Without You” see below]