We’ve made more than the Earth has grown

Anthropogenic mass now exceeds living biomass, study finds.

Among its other dubious distinctions, the year 2020 marked the approximate tipping point between anthropogenic mass and living biomass, scientists say.

The Israeli team has calculated that the mass of human-made products exceeds that of all of the Earth’s plants, microorganisms, people and animals.

And this mass is now doubling around every 20 years, they write in the journal Nature. At that rate it could be more than triple that of the Earth’s dry biomass by 2040.

Defined as “the mass embedded in inanimate solid objects made by humans (that have not yet been demolished or taken out of service)”, anthropogenic mass includes infrastructure and products made with concrete, asphalt, bricks, metals, glass and plastic.

Construction materials comprise the vast bulk of it, and building and infrastructure mass recently surpassed that of all trees and bushes. Plastic goods outweigh all terrestrial and marine animals put together.

The researchers, led by Emily Elhacham from the Weizmann Institute, estimate that humanmade mass in New York City roughly equals that of all the world’s fish, and Egypt’s Great Pyramid of Giza equates to a temperate forest about the size of Kyoto, Japan.

The team merged data from other surveys to make their comparisons and create a complete picture, estimated from the beginning of last century in teratonnes (each equivalent to 1000 gigatonnes).

It’s estimated that we have halved plant mass through deforestation and other landuse changes, from around two teratonnes to one, since the first Industrial Revolution.

In 1900, the team reports, anthropogenic mass comprised 3% of the Earth’s biomass. It’s taken just 120 years to reach this tipping point.

“Given the empirical evidence on the accumulated mass of human artifacts, we can no longer deny our central role in the natural world,” says senior author Ron Milo. “We are already a major player and with that comes a shared responsibility.”