REHOVOT, ISRAEL—December 9, 2020—The mass of all human-produced materials – concrete, steel, plastics, asphalt, etc. – has now grown to equal the mass of all life on the planet, its biomass. According to a new study from the Weizmann Institute of Science, we are exactly at the crossover point, and humans are currently adding buildings, roads, vehicles, and products at a rate that is doubling every 20 years, leading to a “concrete jungle” that is predicted to reach over 2 teratonnes (2 million million) – or more than double the mass of living things – by 2040.
The study, published in Nature, was conducted in Prof. Ron Milo’s lab in the Department of Plant and Environmental Sciences by Emily Elhacham and Liad Ben Uri. It shows that, at the outset of the 20th century, human-produced “anthropogenic mass” equaled around 3% of the total biomass. How did we get from 3% to an equivalent mass in just over a century? Not only have we humans quadrupled our numbers in the intervening years, the things we produce have far outpaced population growth: Today, on average, for every single person on the globe, a quantity of anthropogenic mass greater than their body weight is produced every week.
The upswing is marked from the 1950s on, when building materials like concrete and aggregates became widely available. In the “great acceleration” following World War II, spacious single-family homes, roads, and multi-story office buildings sprang up around the U.S., Europe, and other countries. That acceleration has continued for more than six decades, and the concrete and aggregate materials, in particular, are major components of anthropogenic mass.
“The study provides a sort of big-picture snapshot of the planet in 2020. This overview can provide a crucial understanding of our major role in shaping the face of the Earth in the current age of the Anthropocene. The message to both the policy makers and the general public is that we cannot dismiss our role as a tiny one in comparison to the huge Earth. We are already a major player and I think with that comes a shared responsibility,” says Prof. Milo.
Referring to the dynamics of the human-made materials in our world as a “socio-economic metabolism,” the study invites comparison with the way natural materials flow through the planet’s living and geologic cycles. “By contrasting human-made mass and biomass over the last century, we bring into focus an additional dimension of the growing impact of human activity on our planet,” says Elhacham.
Prof. Milo states, “This study demonstrates just how far our global footprint has expanded beyond our ‘shoe size.’ We hope that once we all have these somewhat shocking figures before our eyes, we can, as a species, take responsibility.”
Prof. Milo and Elhacham teamed with graphic designer Itai Raveh to create a website called anthropogenicmass to put the data in context and explain it clearly and simply.
Prof. Ron Milo’s research is supported by the Mary and Tom Beck – Canadian Center for Alternative Energy Research, which he heads; the Zuckerman STEM Leadership Program; the Larson Charitable Foundation New Scientist Fund; the Ben B. and Joyce E. Eisenberg Foundation; the Yotam Project; the Ullmann Family Foundation; Dana and Yossie Hollander; Sonia T. Marschak; and the European Research Council. Prof Milo is the incumbent of the Charles and Louise Gartner Professorial Chair.