Flux continu

J’ai l’habitude de voir les écologistes et les futurologues parler des limites de la croissance (« The Limits to Growth »). Je suis moins habitué à voir des spécialistes de l’investissement mentionner des recherches liées aux limites de la croissance. C’est pourtant ce qu’a fait récemment Joachim Klement dans sa lettre d’information quotidienne. Bien entendu, quiconque écrit sur les limites de la croissance doit d’abord procéder à toutes les vérifications d’usage. En effet, la combinaison des mots « limites » et « croissance » dans le titre a suscité un grand nombre de réactions critiques, allant de la déformation pure et simple de l’ouvrage à l’incompréhension du modèle de dynamique des systèmes qui le sous-tend.

I’m used to environmentalists and futurists writing about The Limits to Growth. I’m less used to seeing investment writers mention research that’s linked to The Limits of Growth. But that’s what Joachim Klement did in his daily newsletter recently.

Before you read this, a word of caution. You may want to prepare yourself a stiff drink and sit down before you read the following. I think most people who read this will at some point in their life heard about the Club of Rome’s Limit to Growth publication from the 1970s. Back then, the Club of Rome asked the MIT to produce a series of forecasts for the world’s industrial and services output, food production, and pollution levels to the year 2100. Almost from the get-go, these forecasts were derided as scaremongering and flat out wrong. But were they really?

Learning about the Limits to Growth

I’m used to environmentalists and futurists writing about The Limits to Growth. I’m less used to seeing investment writers mention research that’s linked to The Limits of Growth. But that’s what Joachim Klement did in his daily newsletter recently. Of course, anyone who writes about Limits of Growth has to do all the usual disclaimers first. This is because the combination of the words “limits” and “growth” in the title produced a lot of critical responses, on a range from straight-up hatchet jobs which misrepresented the book, to people who didn’t appear to understand the systems dynamics model that sat behind it.

Published 1972 – The message of this book still holds today: The earth’s interlocking resources – the global system of nature in which we all live – probably cannot support present rates of economic and population growth much beyond the year 2100, if that long, even with advanced technology. In the summer of 1970, an international team of researchers at the Massachusetts Institute of Technology (MIT) began a study of the implications of continued worldwide growth. They examined the five basic factors that determine and, in their interactions, ultimately limit growth on this planet-population increase, agricultural production, nonrenewable resource depletion, industrial output, and pollution generation. The MIT team fed data on these five factors into a global computer model and then tested the behaviour of the model under several sets of assumptions to determine alternative patterns for humankind’s future. The Limits to Growth is the nontechnical report of their findings. The book contains a message of hope a

After 50 years, there is still an ongoing debate about the Limits to Growth (LtG) study. This paper recalibrates the 2005 World3-03 model. The input parameters are changed to better match empirical data on world development. An iterative method is used to compute and optimize different parameter sets. This improved parameter set results in a World3 simulation that shows the same overshoot and collapse mode in the coming decade as the original business as usual scenario of the LtG standard run. The main effect of the recalibration update is to raise the peaks of most variables and move them a few years into the future. The parameters with the largest relative changes are those related to industrial capital lifetime, pollution transmission delay, and urban-industrial land development time.

L’auteur du fameux rapport « The Limits To Growth » fait le point, 50 ans après…

Le rapport Meadows est le livre fondateur des actions de transition écologique. En voici un résumé destiné aux lycéens.

conférence de Dennis Meadows, analyste des systèmes, initiateur et co-auteur du rapport Les limites de la croissance, Club de Rome, 1972 lundi 19 septembre 2022 ENS de Lyon, amphithéâtre Mérieux