50th Anniversary

‘The Limits to Growth’

[Only rarely does a book truly change the world. In the nineteenth century, such a book was Charles Darwin’s On the Origin of Species. For the twentieth century, it was The Limits to Growth. Not only did this best-selling 1972 publication help spur the environmental movement, but it showed that the underlying dynamics of the modern industrial world are unsustainable on the timescale of a couple of human lifetimes. This was profoundly important information, and it was delivered credibly and clearly, so that every policy maker could understand it. Sadly, the book was rejected by powerful people with vested interests in the Western growth-based economic model that was overtaking the rest of the world. Today people are starting to see the results of that rejection.

Of the book’s four authors, only Dennis Meadows and Jørgen Randers are active (Donella Meadows died in 2001). Richard Heinberg recently spoke with Dr Meadows, on the occasion of the fiftieth anniversary of the publication of The Limits to Growth. Excerpts:]

Richard Heinberg: Dennis, it is an honour to have this opportunity to interview you. Congratulations on having co-authored the most important book of the past century. I’m delighted that you’re willing to reply to a few questions.

First, how is reality tracking with the scenarios you and your colleagues generated 50 years ago?

Dennis L. Meadows: There have been several attempts, recently, to compare some of our scenarios with the way the global system has evolved over the past 50 years. That’s difficult. It’s, in a way, trying to confirm by looking through a microscope whether or not the data that you gathered through a telescope are accurate. In fact, accuracy is not really the issue here. Our goal in doing the original analysis was to provide a conceptual framework within which people could think about their own options and about the events that they saw around them. When we evaluate models, we always ask whether they’re more useful, not whether they’re more accurate.

Having said that, I will also say that the efforts which have been undertaken have generally concluded that the world is moving along what we termed in our 1972 report to be the standard scenario. It’s an aggregated image of the global system, showing growth from 1972 up to around 2020, and then, over the next decade or two, the principal trends peaking out and beginning to decline. I still find that model very useful in understanding what I read in the papers and in trying to think about what’s coming next.

RH: Generally, when it comes to discussions about environmental impacts on society, resource depletion gets a lot less attention than pollution. Nearly everybody talks about climate change these days, but the background assumption seems to be that, if we reduce emissions to “net zero,” we can continue living essentially as we do now—with a consumer culture, 8 billion people, and cruise ships (hydrogen powered, of course). There’s very little discussion in the mainstream—even among most scientists, it seems to me—about how growing population and consumption will lead to a series of depletion crises even if we somehow avert the worst climate impacts. How do you see the impacts of depletion and pollution developing as constraints on future growth?

DLM: I would say that depletion and pollution are already constraints on future growth. Take just oil, for example. In the ‘90s, the average price was about $30 a barrel. We’re now in the vicinity of $100 a barrel (before the outbreak of Russia-Ukraine war), even taking inflation into account. That is beginning to put a significant damper on investment decisions. And plus, there is of course, no possibility of avoiding climate change, even if we did reduce emissions to net zero. The lifetime of CO2 in the atmosphere (its half-life is about 120 years) means we’re going to have to live for the rest of this century with the consequences of almost everything we’ve dumped into the atmosphere up until now.

The last time the concentration of greenhouse gases in the atmosphere was this high was about 4 million years ago. There were no humans around, and sea level was about 60 feet higher than it is today. This is not science fiction. We know that if the Antarctic ice sheet melts off, it will raise global sea levels by about 190 feet. That will add, of course, to the expansion of the water in the oceans which is coming from warming temperatures. We also see that the Arctic ice sheet is melting. And there’s absolutely no reason I’ve seen to imagine other than that the effects of current warming will accelerate that process.

However, it is useful to imagine (although it’s a fantasy) that we could eliminate climate change as an issue. Even then, major changes would be required. If you read the papers and look at the data, we see that natural resources are deteriorating on every single continent. We’re far above sustainable levels. Even if we could avoid climate change, there is no possibility of sustaining 8 billion people at anything near the living standards we’ve come to expect. There have been some academic exercises to calculate how many people the earth could support. That’s really a silly sort of exercise, because it ignores most of the values and goals that we have for making human life on this planet worthwhile: equity, liberty, welfare, human health. These things are all intimately affected by overpopulation. I don’t know what a sustainable population level is now, but it’s probably much closer to a billion people, or fewer, if we aspire for them to have the kind of living standards and the political circumstances that we enjoy in the West.

Depletion in the future is probably going to manifest most directly through what look like political forces. As countries like the United States and China become dependent on imports to sustain their living standards, which they are already with respect to oil, they will begin to implement political, military, and economic measures to gain control over those assets abroad. And that’s certainly going to bring us into conflict.

RH: The Limits to Growth was heavily scrutinised and criticised. Much of the criticism was unfair and based on numbers from the book that were taken out of context and treated as forecasts—which they explicitly weren’t. But I wonder, with 50 years of hindsight, if any critics made you rethink some of your early assumptions or conclusions?

DLM: Of course, I’ve often wondered how I would do things differently if I knew back in 1972 what I know now, and were once again constructing a team and organising an effort to develop and analyse a global model. By and large, I think we made the right choices. I’ll talk in a moment about energy where, I think some important changes could have been made. One of our crucial assumptions was to look at the globe as a whole, and not try to differentiate amongst regions or countries. In hindsight, I think that was the right thing to do—although it did, of course, open us up to criticism. As little as we know about long-term global trends, we know even less about the dynamics of international transfers of people, finance, resources, energy, and so forth. So, trying to make a multinational model for the long term is going to leave you with an extremely complicated set of assumptions, all of which are based on ignorance, and that’s not a very useful model.

RH: The Integrated Assessment Reports of the Intergovernmental Panel on Climate Change (IPCC) are not systems models like World3 (the model used for The Limits to Growth) and do not consider the possibility of de-growth, only growth. Can you reflect on the differences in modeling approaches and what implications they have—for example, for the most extreme scenarios for greenhouse gas emissions?

DLM: There are profound differences between what we did and the modelling which has been carried out in support of the IPCC. I respect that effort enormously. I know many of the people involved in trying to model long-term climate change. They are excellent scientists, and they’re doing good work. They have generated much useful new knowledge. But the nature of their analysis is just totally different from what we did. It wouldn’t be too much of an exaggeration to say that the IPCC model starts first with what is politically acceptable, and then tries to trace out its scientific consequences, whereas we looked at what was scientifically known, and then tried to trace out its political consequences.

The IPCC model leaves many things exogenous. To use it you have to specify population growth assumptions, economic GDP level assumptions, and so forth. We worked very hard to make the important determinants of our model endogenous. It means that it evolves over time in response to changes that are occurring within the model. Making the important variables, like population, exogenous saves you a lot of criticism. You can give a bunch of different scenarios, and within that set, almost any politician will find something that they like.

The IPCC scenario is just telling us about climate change, and does not get into other issues. We were trying to provide an overall framework. So, they’re both useful efforts, just totally different. It’s like picking up a hammer and picking up a paintbrush, and asking which is better. And of course, the answer is, each has its own purposes.

RH: The Limits to Growth model just has “resources” as inputs to the economy, with energy included as a resource. I wonder if you see energy as special, as it takes energy to access all other resources, such as minerals. Would you think resource declines in general will follow energy declines specifically?

DLM: The most serious omission in our model, as far as I now understand it, was energy. We lumped all forms of energy implicitly into either the nonrenewable resource sector, or, in some farfetched way, the agricultural sector. That implicitly assumes that energy is infinitely substitutable—an assumption the economists make all the time, but which is, of course, totally erroneous.

RH: In rereading your book, I was struck by the excellent recommendations you made, starting on page 161. If only these had been adopted back then by policy makers globally! Unfortunately for us all, they weren’t, for the most part (though some successful efforts were made to slow population growth). Now, 50 years on, do you think different recommendations are appropriate?

DLM: I went back and looked at all three editions of our book. I couldn’t find anywhere that set of recommendations, excellent or otherwise. [RH Note: Dennis is correct here, of course: there are no “recommendations” per se, merely hypothetical conditions, such as the application of policies to produce an equalization of birth and death rates starting in 1975, that were fed into the scenarios in an attempt to produce a stable world condition throughout the 21st century.] However, whatever it was that we recommended back then certainly is not relevant now. In 1972, the impact of humanity on the globe was probably below sustainable levels, and the goal at that time was to slow things down before we hit the limit. Now it’s clear that the scale of human activities is far, far above the limit. And our goal is not to slow down, but to get back down: to find ways to manouvre the system, in a peaceful, equitable, hopefully fairly liberal way, and bring our demands back down to levels that can be borne by the planet. That’s a totally different question than the one we addressed. It would require a totally different kind of model than the one we built, and a totally different set of books than the ones we wrote.

RH: Do you think policy makers are any more open now than they were then?

DLM: It’s not a question of whether policymakers are open or not; it’s whether they’re more likely now to take constructive action than they were 50 years ago. That’s a complex question, and I don’t know the answer. Action requires not just openness, but also resources and concern. I’ve been able to convince people that, for example, climate change is coming. They don’t take action, not because they don’t believe me, but because they just don’t care. They’re focused on a short-term perspective within which the current system is giving them the power and the money they aspire to. They see no need for change.

[Source: Resilience]

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Vol 54, No. 42, April 17 - 23, 2022