The return of "The Limits to Growth"
The return of interest in "The Limits to Growth" continues. After decades of ridicule and insults, the value of the 1972 study and of its sequels is more and more recognized. The latest item in the series of revisitations is the article published by Debora McKenzie in the New Scientist on Jan 10, 2012 and titled "Boom and Doom, revisiting prophecies of collapse" (can be read on the New Scientist site after registration)
by Ugo Bardi | Jan 10 2012 by Cassandra's legacy in Energy Bulletin | Jan 10 2012
The main results of the "base case" scenario of "The Limits to Growth" study, from a recent article on theNew Scientist by Debora McKenzie (available upon registration)
On the whole, the article by McKenzie is very well done and it summarizes all the main points of the story: how Limits never made the mistakes it was accused to have made, how the study was demonized, and how its scenarios are still relevant to our situation today. The article has been extensively researched and it cites the opinion of most of the researchers who have been working on the reappraisal of the study and of its methods, including my book, "The Limits to Growth Revisited".
A point that is less than satisfactory in the New Scientist's article is about the relation of the Limitsscenarios with the present findings of climate science. It says that Limits "was too optimistic about the future impact of pollution," but I think this is not the case. The study did contain at least one scenario in which economic collapse took place because of the rapid rise in pollution. But the main point is thatLimits was perhaps the first study able to identify the interaction of pollution and the industrial system that produces it. What the authors of Limits called "persistent pollution" in 1972 could later be identified with the forcing effect of greenhouse gases. It is not possible, today, to say whether the economy will collapse because of resource depletion or because of global warming; but that the terms of the dilemma were already clarified in 1972 must be considered as a remarkable intuition!
The other point that connects "The Limits to Growth" to climate science is the demonization treatment that the study received after its publication. This point is well covered in McKenzie's article. The smear campaign set up against Limits and its authors is surprising similar to the one unleashed in our times against climate science and against climate scientists. The only difference is that the methods used nowadays against science are much more aggressive. The authors of "The Limits to Growth" were often ridiculed and insulted; occasionally they also received death threats, but the level of abuse that climate scientists have been receiving in recent times is much higher. That is, perhaps, because the consequences of global warming on our society could be much more radical and fearsome than anything that Limits had foreseen decades ago.
This said, it is clear that we can learn a lot from the story of the Limits and its demonization. Unfortunately, one of the things we learn from history is that we almost never learn from history.
Boom and doom: Revisiting prophecies of collapse
Debora MacKenzie, New Scientist
AT THE beginning of the 1970s, a group of young scientists set out to explore our future. Their findings shook a generation and may be even more relevant than ever today.The question the group set out to answer was: what would happen if the world's population and industry continued to grow rapidly? Could growth continue indefinitely or would we start to hit limits at some point? In those days, few believed that there were any limits to growth - some economists still don't. Even those who accepted that on a finite planet there must be some limits usually assumed that growth would merely level off as we approached them.
These notions, however, were based on little more than speculation and ideology. The young scientists tried to take a more rigorous approach: using a computer model to explore possible futures. What was shocking was that their simulations, far from showing ...
... These explosive conclusions were published in 1972 in a slim paperback called The Limits to Growth. It became a bestseller – and provoked a furious backlash that has obscured what it actually said. For instance, it is widely believed that Limits predicted collapse by 2000, yet in fact it made no such claim. So what did it say? And 40 years on, how do its projections compare with reality so far?
... Forty years on from its publication, it is still not clear whether Limits was right, but it hasn’t been proved wrong either. And while the model was too pessimistic about birth and death rates, it was too optimistic about the future impact of pollution. We now know that overshoot – the delayed response to problems that makes the effects so much worse – will eventually be especially catastrophic for climate change, because the full effects of greenhouse gases will not be apparent for centuries.
There will be no more sequels based on World3, though. The model can no longer serve its purpose, which was to show us how to avoid collapse. Starting from the current conditions, no plausible assumptions produce any result but overshoot. “There is no sense in only describing a series of collapse scenarios,” says Dennis Meadows, another of the original authors of Limits.
... Instead of declaring we are doomed, or proclaiming that technology will save us, we should explore the future more rigorously, says Bar-Yam. We need better models. “If you think the scientific basis of those conclusions can be challenged, then the answer is more science,” he says. “We need a much better understanding of global dynamics.”
We need to apply that knowledge, too. The most important message of Limits was that the longer we ignore the problems caused by growth, the harder they are to overcome. As we pump out more CO2, it is clear this is a lesson we have yet to learn.
Debora MacKenzie is a consultant for New Scientist based in Brussels, Belgium (4 January 2012)
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