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. http://www.unh.edu/ipssr/index.html   The model runs on "Stella". A save disabled version of the program can be downloaded for free from High Performance Systems web site. http://www.hps-inc.com/customer_center/index.htm