Everything humanity has built now outweighs living biomass: Study
In 120 years, the works of humankind have gone from weighing only as much as three per cent of Earth's biomass, to equalling and now outweighing it.
After a few millennia it has finally happened: Everything humankind has built or produced is about to start outweighing all of Earth’s overall living biomass – if it hasn’t already.
That’s according to a study published in the journal Nature, which says 2020 is likely to be that tipping point, though with a margin of error on either side of that date.
“The exact timing of the point at which anthropogenic mass surpasses living biomass is sensitive to the definitions of biomass and anthropogenic mass; for example, whether they are defined on a wet- or dry-mass basis, the researchers write. “However, we find that under a range of definitions, the point of transition is in either the past decade or the next two.”
“Anthropogenic” roughly means “human-produced,” and the researchers say that, for the purposes of their study, that includes the dry-weight of concrete, aggregates, bricks, asphalt, metals, glass, plastic, and wood used for paper and industry – all the things that go into building a global civilization.
The researchers estimate overall living biomass on Earth comes to around 1.1 teratonnes, or 1.1 trillion tonnes, overwhelmingly made up of plants and shrubs. In 2020, based on a five-year average, man-made mass was increasing by around 30 gigatonnes, or 30 billion tonnes.
“On average, for each person on the globe, anthropogenic mass equal to more than his or her body weight is produced every week,” the researchers say.
The dry-weight of everything humankind has produced is now roughly equal to all living biomass, and is still growing. Image: Ivan Bandura/Unsplash.
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Though humankind has been building and making things for thousands of years, our works only made up around 3 per cent of the world’s biomass in 1900. Since then, however, production has gradually increased, and the researchers say they can even pinpoint exact periods where certain kinds of man-made mass took a jump, such as world wars and particular economic periods.
“For example, the gradual shift from construction dominated by bricks to concrete, which tilted in favour of concrete in the mid-1950s, is clear, as is the emergence of asphalt as a major road pavement material from the 1960s,” the researchers report.
The rise after the Second World War was so noticeable and sustained, the researchers add, that they refer to that period as the ‘Great Acceleration.’
The increase in human-made products and materials also has to be measured against humanity’s impact on the environment, specifically plant biomass.
“Since the first agricultural revolution, humanity has roughly halved the mass of plants,” the researchers say. “While modern agriculture utilizes an increasing land area for growing crops, the total mass of domesticated crops is vastly outweighed by the loss of plant mass resulting from deforestation, forest management and other land-use changes. These trends in global biomass have affected the carbon cycle and human health.”
The study, “Global human-made mass exceeds all living biomass,” was published online on December 9th, 2020.
Thumbnail credit: Lucas van Oort via Unsplash
