.SystemDynamics.WorldDynamics.World3.Scenario_9

Information

We now want to combine the measures of Scenario #6 and Scenario #8.

References:

1. Meadows, D.H., D.L. Meadows, J. Randers, and W.W. Behrens III (1972), Limits to Growth: A Report for the Club of Rome's Project on the Predicament of Mankind, Universe Books, New York, 205p.
2. Meadows, D.L., W.W. Behrens III, D.M., Meadows, R.F. Naill, J. Randers, and E.K.O. Zahn (1974), Dynamics of Growth in a Finite World, Wright-Allen Press, 637p.
3. Meadows, D.H., D.L. Meadows, and J. Randers (1992), Beyond the Limits, Chelsea Green, 300p.
4. Meadows, D.H., J. Randers, and D.L. Meadows (2004), Limits to Growth: The 30-Year Update, Chelsea Green, 368p.

In order to accomplish this change, you need to modify the three tables as done earlier:

parameter Real p_ppoll_tech_chg_mlt[:] = {-0.04,-0.04,0,0} "Persistent pollution technology change multiplier";,

parameter Real p_res_tech_chg_mlt[:] = {-0.04,-0.04,0,0} "Resource technology change multiplier";.

parameter Real p_yield_tech_chg_mlt[:] = {0,0,0.04,0.04} "Yield technology change multiplier";.

We also need to reset one more of the switching times in the model:

parameter Real t_land_life_time(unit="yr") = 2002 "Land life time";.

Simulate the model from 1900 until 2100, and display the same variables as in the book Limits to Growth: The 30-Year Update at page 245:

This seems to have done the trick. The population no longer declines during the 21^st century. Is this effort sustainable?

To answer this question, let us simulate the model once more, this time from 1900 until 2500:

The effort is not sustainable in the long run. As we continue to produce industrial goods in order to maintain a high standard of living, we continue to use up the non-recoverable resources, albeit at a much slower rate. Eventually, these resources get exhausted, and at that time, we return to a life in misery.