2 mei 2013

Scenarios as a warning: Limits to growth

Source: ClubOfRome

Source: ClubOfRome

Probably the most controversial and most famous scenario study published is the Limits to Growth report. It was published as a book in 1972 and presents scenarios, based on computer modelling, on the consequences of economic and population growth. The book was funded by the Volkswagen Foundation and produced by the Club of Rome. It’s authors are Donella H. Meadows, Dennis L. Meadows, Jørgen Randers, and William W. Behrens III, a team of analysts at the time working for MIT.

For the scenarios five variables were examined: world population, industrialisation, pollution, food production and resource depletion. The assumptions were made that exponential growth would continue and that through technological innovation the availability of resources would only grow linearly. In total, the original study presented 12 possible futures from 1972 – 2100. In 2004 an update was published showing 9 scenarios.



Many people believed the Limits to Growth report predicted a world collapse by the end of the 20th century. But the purpose of the Limits to Growth report was not to make predictions, but to explore how exponential growth interacts with finite resources. And how humanity will deal with this finite resources. This was explained by the authors as follows: “For example, a population growing in a limited environment can approach the ultimate carrying capacity of that environment in several possible ways. It can adjust smoothly to an equilibrium below the environmental limit by means of a gradual decrease in growth rate, as shown below. It can overshoot the limit and then die back again in either a smooth or an oscillatory way, also as shown below. Or it can overshoot the limit and in the process decrease the ultimate carrying capacity by consuming some necessary non-renewable resource, as diagrammed below. This behaviour has been noted in many natural systems. For instance, deer or goats, when natural enemies are absent, often overgraze their range and cause erosion or destruction of the vegetation.”

The authors not only presented the possibility that the human population and economic system might collapse, but also that this collapse could be avoided with a combination of changes in behaviour, policy and technology.

The club of Rome published this video on the original message of Limits to Growth:

The response to the report varied strongly. Some say the publication of the report lead up to current global movements like environmental awareness, sustainability and CSR.  Limits to Growth was one of the first studies combining many factors and disciplines. It introduced the approach of ‘system dynamics’ modelling and quantative scenario analysis into the scientific environmental discipline. Millions of the book’s copies were sold and it was translated into over 30 languages. Critics, however, argued that the computer model was incorrect and some even questioned the integrity of the authors. Also the authors were accused of trying to ‘predict world’s end’.

Now, 40 years later, the debate still hasn’t ended. Many studies are published on updates on the computer model and whether the results are to be trusted. A 2008 publication called ‘A comparison of the Limits to Growth with thirty years of reality’, stated that “30 years of historical data compares favorably with key features of a business-as-usual scenario called the “standard run” scenario, which results in collapse of the global system midway through the 21st Century.” In 2009, the Dutch Environmental Assessment Agency concluded in their report “Growing within Limits” that “Technical and economically feasible options are available to meet the challenge to avoid these problems. The main issue is that of creating institutional and policy conditions for a more sustainable economy.”


I am no expert on computer models, but as a foresight expert what I find interesting about the Limits to Growth publication is that it lead up to its purpose: creating awareness for environmental challenges. It launched a world wide debate on the future of our planet and of humankind. It did so because it provided strong, science based scenarios for what the future of humankind might look like. It painted a picture of where humanity might be headed, which, unfortunately, wasn’t a pretty picture in most scenarios. By doing so, it influenced the public debate on a global scale and in way few scenario studies ever have.