365 Days of Climate Awareness 100 – The Limits to Growth

In the early 1970’s the Club of Rome, an informal group of international people of business, government and academics, commissioned a group of system dynamicists to model the planet as a natural and societal system, to develop some sense of the trajectory of global society in decades to come. Leading the team was an MIT professor, Donella Meadows. Their results were published in 1972’s “The Limits to Growth”, a short book which hits all the harder for its simplicity. They found that humans, in terms of population and the physical costs of the global economy, were headed toward overshoot of the planet’s carrying capacity, and faced the likelihood of a devastating 21st-century economic and population crash. 

World3 model interconnections.

The book became a worldwide bestseller and faced furious attacks over the years to come. Most of those were simply outrage at the thought of any limits at all on sunny optimism, cloaked in nitpicking about particular aspects of the book’s argument, such as assumptions of linear depletion of resources (which were never intended to be predictions). The argument of the book is not that mineral resources were going to dwindle smoothly to zero. The argument lies in the dynamics of a complex system, with a mindbending array of feedbacks, both positive and negative.

World3 model, standard run.

The crux of the system’s behavior lies in two main behaviors. First is the difficulty of obtaining increasingly scarce resources, where they are not zero, but are more costly in terms of capital and environmental destruction to obtain (example: peak oil). Second is the increasing degradation of the environment, which becomes less healthy for humans and most life as we know it, and introduces problems which require increasing amounts of capital to remediate (examples: Superfund sites, and, of course, global warming).

World3 model, doubled reserves.

If economic growth is not moderated within the model, under the assumption of intelligent planning, it predicts a dramatic overshoot and crash of economic activity and population between the fourth and sixth decades of this century. Over multiple runs, the Meadows team doubled and more the available resources. This did not change the system’s behavior. On the contrary, increased resources merely pushed the peak a little further into the future, and worsened the crash.

It is fear and outrage at this overshoot-then-crash prediction which led to an almost pathologically ferocious backlash which lasted generations but did not address its fundamental soundness. In the United States this pathology contributed to the election, at the critically worst possible moment, of the politically gifted but unintelligent optimist Ronald Reagan, who categorically denied any sense of responsibility of humans to the planet we inhabit.

Tomorrow: Limits to Growth revisited (30-year update).

Be brave, and be well.

Text of the book