Weight of the human world is heavy on scientists’ minds

The sum total of human endeavors weighs 30 trillion metric tons, an international team of researchers reported last week in The Anthropocene Review.

The study represents a first effort to quantify the technosphere, meaning everything people have constructed, made, or shaped with their activities to support human life.

That’s an enormous job because the technosphere includes everything from buildings, power lines, and airplanes to jackhammers, Lego bricks, and ballpoint pens. It includes both living (domestic pigs, Labradoodles, apple trees) and nonliving (sewing machines, backhoes, the Crown Jewels of the United Kingdom) components.

It encompasses the infrastructure of cities and suburbs, but also farm fields, managed forests, dikes and polders, and ships at sea. It extends underground (coal mines, sewer lines) and even into outer space (GPS satellites, the Mars rovers).

According to the study, the mass of the technosphere is five orders of magnitude greater than the biomass of our own species. In other words, for every pound of human flesh, there’s at least a million pounds of human stuff.

If the technosphere were spread out evenly over the whole planet, it would amount to over 50 kilograms (110 pounds) per square meter of Earth’s surface, say the study’s authors (who include Andrew Revkin, a member of Anthropocene magazine’s advisory board).

Different geological eras have distinct fossil records. So, the researchers ask, what will be the characteristic fossils of the Anthropocene? They suggest the concept of “technofossils,” human-created objects like books and mobile phones that could leave stratigraphic clues for future scientists to interpret.

There are more kinds of technofossils than there are current biological species, far more than known biological fossils, and maybe more than all life forms that have ever lived, they say.

Those are jaw-dropping figures. But perhaps even more unsettling—though in a quieter way—is how the paper’s descriptions upend the usual thinking about familiar aspects of daily life. For example, just as wells are pipelines for the “managed flux” of hydrocarbons or water, subways are pipelines for the managed flux of human beings.

Commuters undertake “constant daily migrations with hydrocarbon-powered vehicles,” calling to mind the way marine plankton rise and fall in the water column in concert with the light-dark cycle.

The researchers’ catalog of the technosphere includes not just physical objects but vacancies: the climate-controlled air inside of buildings, fished-out volumes of seawater, trawler scours on the ocean floor.

And waste in the technosphere isn’t limited to trash in landfills but also encompasses the accumulation of carbon dioxide and methane in the atmosphere, and microscopic plastic debris and radiological fallout in the oceans.

As massive and far-reaching as the active technosphere is, that waste component is where the problem really lies, the researchers suggest.

“The technosphere can be said to have budded off the biosphere and arguably is now at least partly parasitic on it,” said study coauthor Mark Williams in a University of Leicester press release. “Compared with the biosphere, though, it is remarkably poor at recycling its own materials.”

In the biosphere, highly efficient systems break down wastes excreted by living organisms and the bodies of dead ones. Even when animal species alter their environment—think bird nests, beaver dams, gopher tunnels, chimpanzee tools—the materials used are recycled fairly quickly. Not so in the technosphere.

The researchers call out this difference to sound an alarm, and they’re right to do so. But the problem they articulate may contain its own solution. What’s needed is more recycling, not just literally but in a conceptual sense: make the technosphere behave more like the biosphere from which it came.

Source: Zalasiewicz J et al. “Scale and diversity of the physical technosphere: A geological perspective.” The Anthropocene Review2016.
Header image: The WEEE Man, a 3.3-tonne structure which represents the amount of waste electrical and electronic equipment (WEEE) the average British household throws away in a lifetime. Credit: Justin Warner via Flickr.

Get the latest sustainability science delivered to your inbox every week

You have successfully signed up

Become a Member Today >>

You have Successfully Subscribed!

Share This

Share This

Share this post with your friends!