The Limits to Growth: 50 years on

In 1972, the Club of Rome published The Limits to Growth. It was one of the first major reports to suggest that the earth is not capable of sustaining its projected human population. What part did it play in our understanding? Can it still tell us something about our future, when all major political parties still base their programmes on the idea of continuing growth?

The Club of Rome was founded in the late 1960s as a global gathering of ‘scientists and thought leaders concerned to identify holistic solutions to complex global issues and promote policy initiatives and action to enable humanity to emerge from multiple planetary emergencies’. Their huge ambition was to try to understand, and help manage, the future of mankind itself.

The world model

The Limits to Growth was their first major project. They commissioned a team at the Massachusetts Institute of Technology to build what was, for its time, a very sophisticated computer model (their ‘world model’). This mapped a host of factors, like population growth, capital investment, food production, resource reserves and depletion rates, and pollution. Most importantly, the model quantified the ways the factors affected each other. They then used the model to test a variety of assumptions about how those factors might change over time.

Their key conclusion was that any scenario which involved growth of any of the main factors would lead to some form of economic or social collapse before the end of the 21st century.

Exponential growth

One critical concept the report introduced into public discussion was exponential growth. Even a very small growth rate, if it is sustained, will produce very large results over time. So, a 1.25% annual growth in population takes us from 2 billion in 1950 to 10 billion in 2080. The impact of this on manufacturing, energy needs and food production is evident, but was not often commented on at the time.

Overshoot

A second concept was ‘overshoot’. All these systems have built in time delays. It takes time for humans to notice the unintended consequences of a change, and respond to them. As a result, when exponential growth in one factor (population, industrial development) happens, it tends to expand beyond the capacity of the whole system to sustain it, leading to some form of collapse. This then has a knock-on effect on other systems. So a new industrial technology can generate new kinds of pollution years later, with impacts on health decades beyond that. But these are timescales well beyond the capacity of existing political systems to respond to.

Equilibrium

Their third big idea was equilibrium. They used the model to test a great range of scenarios (what, for example, happens if birth rates fall quickly). After running many scenarios through their model they concluded that any version which depended on growth in the key elements ends, at some point before 2100, in disaster, at least for some people or societies.

So they proposed an alternative, that we should seek a state of equilibrium. This would mean treating the key resources as limited, and seeking to live within those constraints. They argued that in that way we could avoid sudden and uncontrollable collapse, while still satisfying the basic requirements of all the people.

Criticisms

In 1972, criticism of the report focused on three issues:

1. its assumptions were too pessimistic about resource constraints. People pointed out that, in the past, improved exploration techniques had always found new reserves of natural resources as demand increased.

2: it underestimated the ability of technology to increase the efficiency of existing resource use.

3: the model could not account for the human dimension: the political and sociological factors.

There is some truth in those criticisms

Resource supplies have continued to expand, and the list of critical resources has changed. The Club of Rome’s list of 20 economically critical minerals does not include lithium, or any of the rare earths without which most 21st-century technologies could not exist.

However, we are still concerned about the conditions involved in extracting some key minerals, the politics of who controls them, and the pollution associated with them. We would probably now put more weight on access to water, on the availability of healthy agricultural land, and the depletion of the land we are farming now.

On technology, the Club of Rome could not have anticipated some of the major changes of the last 50 years. In 1972, the computer revolution was about to take off, but computers were still huge, expensive and largely restricted to military uses and academic institutions. Since then, they have certainly contributed to more efficient use of material resources, but perhaps increased energy use.

The human dimension remains a problem. This was a technocratic report, which only touched lightly on political issues. One might now argue that some of the predictions have come true but, instead of global collapse, political power has protected some places and people. The disasters are no less real, but suffered disproportionately by some people in some places.

The sustainable model

The Club of Rome calculated that, if seven policy objectives were implemented, population, food and industrial output per capita would all level out at some point in the mid 21st century. There would be resources to provide everyone with a standard of living equivalent to 1972 European levels. The seven policies were:

Stabilise birth rates to match death rates.
Reduce non-renewable resource consumption by three quarters.
Shift economic activity away from material goods towards non resource-based activities – education, health, religion, social interaction and the arts.
Reduce industrial and agricultural pollution by three quarters.
Divert resources to food production in regions where it is currently deemed uneconomic.
In agriculture, prioritise soil enrichment.
Improve design and durability of manufactured goods to reduce resource use and increase recycling.

The challenge

In the abstract, all these objectives seem reasonable, and even self-evident. But progress has not been great. Perhaps the most obvious success has been on controlling birth rates. However, even here, overshoot is substantial. Although in most of the world population growth has stopped, or even reversed, in Africa and the Middle East, numbers are still rising. Global population is predicted to peak and level off around 2080, but by then there will be 2 billion more of us for the earth to sustain.

And in the real world most of the other objectives are contentious. Politics does not naturally distribute resources equally. Few people in Europe or North America would willingly return to real income levels comparable to Europe in 1972. People and countries will fight to retain those advantages.

The agenda the Club of Rome began is huge. Paradoxically it works on a very long timescale but also requires urgent action. Exponential growth means that the time available to solve them is shrinking. One can see the difficulties in our attempts to manage the climate crisis. The COP climate process is a descendant of The Limits to Growth, and we can see in COP how difficult it is for the human race to confront its existential challenges.

The issues the Club faced in 1972 are still with us. Arguably they have mostly got worse, especially for some people. But there is much in that first report which still deserves attention.