{"id":3512992,"date":"2025-05-20T09:55:14","date_gmt":"2025-05-20T09:55:14","guid":{"rendered":"https:\/\/www.resilience.org\/?p=3512992"},"modified":"2025-05-20T09:55:14","modified_gmt":"2025-05-20T09:55:14","slug":"limits-to-growth-was-right-about-collapse","status":"publish","type":"post","link":"https:\/\/www.resilience.org\/stories\/2025-05-20\/limits-to-growth-was-right-about-collapse\/","title":{"rendered":"Limits to Growth was right about collapse"},"content":{"rendered":"

\"\"I\u2019m used to environmentalists and futurists writing about\u00a0The Limits to Growth<\/em>. I\u2019m less used to seeing investment writers mention research that\u2019s linked to\u00a0The Limits of Growth<\/em>. But that\u2019s what\u00a0Joachim Klement did<\/a>\u00a0<\/strong>in his daily newsletter recently.<\/p>\n

Of course, anyone who writes about\u00a0Limits of Growth<\/em>\u00a0has to do all the usual disclaimers first. This is because the combination of the words \u201climits\u201d and \u201cgrowth\u201d 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\u2019t appear to understand the systems dynamics model that sat behind it.<\/p>\n

(I edited\u00a0a special edition<\/a><\/strong>\u00a0of the APF newsletter\u00a0Compass<\/em>\u00a0that looked back at\u00a0Limits to Growth<\/em>. There\u2019s an article in there by Ugo Bardi that goes into the detail of the history of the assault on\u00a0Limits<\/em>\u00a0when it was published.)<\/p>\n

Standard run<\/h3>\n

Klement puts it this way:<\/p>\n

Here is what the model actually predicted. The scientists at the MIT modelled three scenarios [actually 13, including these three\u2013AC]: business as usual (what was then called \u2018standard run\u2019), a technologically enhanced world where technological progress eliminates most limits to growth, and a stabilised world where our economies shift to a sustainable (i.e. non-resource consuming) model by the turn of the century.<\/em><\/p><\/blockquote>\n

The trouble with the \u2018standard run\u2019 is that its 50-60 year outcomes weren\u2019t that good. They suggest that global industrial output will start to decline in the mid-2020s (checks calendar), and that global population will start to decline in the mid-2030s.<\/p>\n

In the 2010s, Graham Turner looked at the standard run against out-turn data, as Klement reminds us, and found it a good fit. Gaya Herrington updated this research in the early 202s\u2014as per my\u00a0Just Two Things piece linked here<\/a><\/strong>\u2014and it was a still a good fit.<\/p>\n

Recalibrating the model<\/h3>\n

Now another group of scientists have gone back to the original World3 model and recalibrated it against the best fit data, which is what has prompted Klement\u2019s article. \u2018Recalibration of limits to growth: An update of the World3 model\u2019, by Nebel et al, is\u00a0published open access<\/a><\/strong>\u00a0in the\u00a0Journal of Industrial Ecology<\/em>.<\/p>\n

The point of doing this is\u2014as they say in their abstract\u2014is<\/p>\n

to better match empirical data on world development.<\/em><\/p><\/blockquote>\n

For assurance, the article goes into detail about their method and their approach, including access to the Python scripts they have used, which have been posted on Github. As they explain:<\/p>\n

Since the model was calibrated with the limited capabilities in terms of computing power and data processing in 1972, it seems interesting to what extent a recalibration of the model is possible and what are the effects of such a recalibration. The data situation has improved enormously since then.<\/em><\/p><\/blockquote>\n

Overshoot and collapse<\/h3>\n

What this means is that the recalibrated model reflects the best available current data.<\/p>\n

Klement explains the approach this way:<\/p>\n

If the recalibrated model deviates significantly from the forecasts of the 1970s, we have made progress. And given the accuracy of the original model, we can also take some comfort that any progress we made is likely to be real and we have truly extended economic growth further into the future.<\/em><\/p><\/blockquote>\n

And the outcomes of this recalibration? Well, they\u2019re not good. Again from the abstract to the article:<\/p>\n

This improved parameter set results in a World3 simulation that shows the\u00a0same overshoot and collapse<\/strong>\u00a0mode in the coming decade as the original business as usual scenario of the LtG standard run. [My emphasis]<\/em><\/p><\/blockquote>\n

Industrial production decline<\/h3>\n

It is worth spelling out the dimensions of this overshoot and collapse. As it happens, there are some handy charts both in Joachim Klement\u2019s article and in the original paper. I\u2019ve reproduced Klement\u2019s versions here because they are easier to read, but the originals are downloadable from the original article.<\/p>\n

The first chart is for industrial production, where the recalibrated version tracks the original to the centimetre, pretty much. Does this matter? Klement does the usual wave towards the fact that we live in a much more services-based economy than we did even when the\u00a0Limits<\/em>\u00a0team did the original study.<\/p>\n

\"\"<\/a><\/p>\n

(Source: Nebel et al, 2023, adapted Klement)<\/em><\/p>\n

Peaking food production<\/h3>\n

I\u2019m not completely convinced of this. As David Mindell observes in\u00a0The New Lunar Society<\/a><\/em><\/strong>\u00a0(I have a review in the works), industrial production has significant multiplier effects on other economic activity, even if this is largely overlooked by economics [p33]. The updated population diagram also follows closely the decline in the mid-2030s that is seen in the\u00a0Limits<\/em>\u00a0base case projection.<\/p>\n

On food production, it<\/p>\n

also seems to be peaking right about now indicating that despite continuous growth in the global population, we are experiencing declining global food production.<\/em><\/p><\/blockquote>\n

Delaying the peak<\/h3>\n

So it\u2019s possible to imagine that one of the reasons why population starts to decline is because there isn\u2019t enough food to go around. It\u2019s also possible to imagine that the higher peak, and faster overshoot, is a result of the intensification of agriculture and food production, which is about the application of technology. As one of the\u00a0Limits<\/em>\u2019 authors, Dennis Meadows, always insisted when asked, technology can delay a peak, but the crash comes harder when it comes.<\/p>\n

\"\"<\/a><\/p>\n

(Source: Nebel et al, 2023, adapted Klement)<\/em><\/p>\n

The third chart here is for \u2018persistent pollution\u2019, which is a modelling shorthand for a range of externalities including CO2 emissions. Here, on the face of it, we have beaten the model: \u2018persistent pollution\u2019 is currently much lower than the World3 standard run. But given that it climbs much higher, and hangs around for much longer, it actually just seems that with better data it turns out that initial effects were less severe but the delays in the system were much greater than the original model assumed.<\/p>\n

\"\"<\/a><\/p>\n

(Source: Nebel et al, 2023, adapted Klement)<\/em><\/p>\n

Downhill from here<\/h3>\n

The last chart assembles something from the data that wasn\u2019t done in the original\u00a0Limits to Growth<\/em>\u00a0work because the concept hadn\u2019t been developed. But it is possible to assemble a Human Development Index from the data, and reference it against the original model and the revised version. It doesn\u2019t come out well.<\/p>\n

\"\"<\/a><\/p>\n

(Source: Nebel et al, 2023, adapted Klement)<\/em><\/p>\n

On this last chart, Klement is most depressed, and I think with good reason:<\/p>\n

If [this chart] is true, it says that today is peak human civilisation, from now on we are going backward on a global level in terms of human development and quality of life, While some countries will continue to improve, other countries and the planet as a whole will start to go backward, ultimately dropping back to similar levels of human development and quality of life as in 1900 by the end of this century.<\/em><\/p><\/blockquote>\n

Tipping point<\/h3>\n

The overall conclusion by the article\u2019s authors is:<\/p>\n

[T]he model results clearly indicate the imminent end of the exponential growth curve. The excessive consumption of resources by industry and industrial agriculture to feed a growing world population is depleting reserves to the point where the system is no longer sustainable. Pollution lags behind industrial growth and does not peak until the end of the century. Peaks are followed by sharp declines in several characteristics.<\/em><\/p><\/blockquote>\n

They also note that the cause of this turning point is resources, not \u2018pollution\u2019:<\/p>\n

This interconnected collapse\u2026 occurring between 2024 and 2030 is caused by resource depletion, not pollution.<\/em><\/p><\/blockquote>\n

They also have an interesting caveat. This is that the way the World3 model works is a through a set of connections that exist within an environment of growth. In an environment of decline, they are likely to reconfigure themselves in different ways. That doesn\u2019t mean that there won\u2019t be a decline\u2014just that the current lines in the model that describe it may not follow quite the same patterns.<\/p>\n

But one final note from me. Economists get over-excited when anyone mentions \u2018degrowth\u2019, and fellow-travellers such as the Tony Blair Institute treat climate policy as if it is\u00a0some kind of typical 1990s political discussion<\/a><\/strong>. The point is that we\u2019re going to get degrowth whether we think it\u2019s a good idea or not. The data here is, in effect, about the tipping point at the end of a 200-to-250-year exponential curve, at least in the richer parts of the world. The only question is whether we manage degrowth or just let it happen to us. This isn\u2019t a neutral question. I know which one of these is worse.<\/p>\n

\u2014<\/p>\n

A version of this article was also published on my Just Two Things Newsletter<\/a>.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

The only question is whether we manage degrowth or just let it happen to us. This isn\u2019t a neutral question. I know which one of these is worse.<\/p>\n","protected":false},"author":128238,"featured_media":3512998,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[79717,213528,79716,79718],"tags":[],"class_list":["post-3512992","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-economy","category-economy-featured","category-energy","category-environment"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.resilience.org\/wp-json\/wp\/v2\/posts\/3512992","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.resilience.org\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.resilience.org\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.resilience.org\/wp-json\/wp\/v2\/users\/128238"}],"replies":[{"embeddable":true,"href":"https:\/\/www.resilience.org\/wp-json\/wp\/v2\/comments?post=3512992"}],"version-history":[{"count":5,"href":"https:\/\/www.resilience.org\/wp-json\/wp\/v2\/posts\/3512992\/revisions"}],"predecessor-version":[{"id":3513000,"href":"https:\/\/www.resilience.org\/wp-json\/wp\/v2\/posts\/3512992\/revisions\/3513000"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.resilience.org\/wp-json\/wp\/v2\/media\/3512998"}],"wp:attachment":[{"href":"https:\/\/www.resilience.org\/wp-json\/wp\/v2\/media?parent=3512992"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.resilience.org\/wp-json\/wp\/v2\/categories?post=3512992"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.resilience.org\/wp-json\/wp\/v2\/tags?post=3512992"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}