Modeling the Future
It has been more than 20 years since the Club of Rome first
produced its model, and came to the conclusion that infinite
growth is not an option, and without strong action the likely
path will be overshoot and collapse. That model has been updated
and is available to run on a PC or Mac. The Meadows have written
an excellent sequel to the original book Beyond
The Limits, Confronting a Global Collapse, Envisioning a Sustainable
Future, which explains the model, , its logic and
its significance, and the corrections that have been made. Two
things stand out in the updated book. In their 20 year update,
they did not have to make any changes that affected the output
quantitatively as the model was still tracking the real world.
There were errors in the models predictions because population
growth has slowed, and technologies have changed in ways that
could not have been foreseen, but the errors tended to cancel
each other out. The other striking fact is the persistence of
the pattern of overshoot and collapse in spite of any reasonable
technological fix that can be engineered at this time. If all
the controls for technological change and resource conservation
are pushed to the limit at 10% change per year, and the implementation
time is cut in half, it is just possible to stabilize some of
the aspects such as food supply, but the standard of living in
general decreases. And those are far more optimistic than our
current political or economic systems can deliver.
Below are three graphs from the model running on Stella. These
are all created from a run using the baseline assumptions of
the model with the exception that the estimated reserves of natural
resources have been doubled. All other factors are consistent
with current conditions and the rates of change in the last 20
years. In this run, food production per capita peaks around 2002
though actual food production does not peak until 2032. The combination
of food stress, pollution, and crowding lead to a decrease in
life expectancy by the year 2028 even though services per capita
and consumer goods per capita increase for another 10 years.
- The World 3 model is available from the University of New
Hampshire web site.
- The model runs on "Stella". A save disabled version
of the program can be downloaded for free from High Performance
Systems web site.