pelicanweblogo2010

Mother Pelican
A Journal of Solidarity and Sustainability

Vol. 22, No. 1, January 2026
Luis T. Gutiérrez, Editor
Home Page
Front Page

motherpelicanlogo2012


Are we on the Edge of Collapse?
Impressive Data from a Recalibration of the
World3 Simulation Model


Ugo Bardi

This article was originally published on
The Seneca Effect, 28 November 2025
REPUBLISHED WITH PERMISSION



One more Seneca Cliff coming soon? If so, we are in for a rough fall. Graph prepared by Claude on the basis of the data by Nebel et al.. Click on the image to enlarge.


Staring at the Cliff right in front of us.

I always say that models are not predictions; they are qualitative illustrations of what the future could be. But as the future gets closer to the present, models can start being seen as predictive tools. It is the weather/climate dichotomy, so aptly exploited to confuse matters by politically minded people in the discussion about climate. Right now, we are getting close to the point that we could forecast a collapse in the same way as we can forecast the trajectory of a tropical storm.

So, you remember how “The Limits to Growth” generated a long term forecast in 1972. Here it is:


Click on the image to enlarge.

The start of the collapse of the industrial production (here calculated in per capita terms) was supposed to be at some moment between 2010 and 2020. A little too early, because we passed that moment. But that calculation was made more than 50 years ago, and it is legitimate to think that it needs some readjustments. That was what Nebel et al did in a recent paper; they recalibrated the same model (World3) on the basis of the available real-world data. And here is their result.


Click on the image to enlarge.

Note the red curve, industrial production. Are we facing the abyss? At first, it looks unlikely, but I compared Nebel’s data with the real-world ones for industrial production, and I had Claude plot them together. The result is shown at the beginning of this post; let me reproduce it here again:


Click on the image to enlarge.

Do pay attention to the other curves of Nebel et al.’s paper. Agricultural collapse will be at about the same time as the industrial one. Population should start collapsing a few years later. Pollution will reach a peak around 2080 at levels some three times higher than the current ones. If this is a good prediction, we are in for a rough ride, a VERY rough ride.

But never forget: even hurricanes may change their trajectory at the last moment, and there are reasons for optimism. Listen to Sabine Hossenfelder, for instance. I think that before making this clip, she smoked something really strong. But who knows? She might be right.


By the same author:

Aurelio Peccei's Last Words ~ A Message of Hope from
the Founder of the Club of Rome


ABOUT THE AUTHOR

Ugo Bardi is emeritus professor of physical chemistry, University of Florence, Italy. He is interested in resource depletion, system dynamics modeling, climate science, and renewable energy. He is member of the scientific committee of ASPO (Association for the Study of Peak Oil) and regular contributor of The Oil Drum and Resilience. His blog in English is called The Seneca Effect. His most recent book in English is Extracted: How the Quest for Global Mining Wealth is Plundering the Planet (Chelsea Green, 2014). He is also the author of The Limits to Growth Revisited (Springer 2011), and is a member of the Club of Rome.


"Nature abhors a vacuum."

— Aristotle (384-322 BCE)
— Spinoza (1632-1677 CE)

GROUP COMMANDS AND WEBSITES

Write to the Editor
Send email to Subscribe
Send email to Unsubscribe
Link to the Group Website
Link to the Home Page

CREATIVE
COMMONS
LICENSE
Creative Commons License
ISSN 2165-9672

Page 3