modelScenario_9
Information
This is Scenario #9 of the WORLD3 model. This scenario starts out with the same assumptions as Scenario #8. Control of the industrial output helped to guarantee a relatively high standard of living for a while longer. Yet, the stressors discussed before finally drag the system down.We now want to combine the measures of Scenario #6 and Scenario #8.
References:
- 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.
- 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.
- Meadows, D.H., D.L. Meadows, and J. Randers (1992), Beyond the Limits, Chelsea Green, 300p.
- 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 21st 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.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | agr_mtl_toxic_index | 1 | Agricultural materials toxicity index |
| Real | assim_half_life_1970 | 1.5 | Pollution assimilation half life in 1970 |
| Real | avg_life_land_norm | 1000 | Normal life span of land |
| Real | des_compl_fam_size_norm | 3.8 | Desired normal complete family size |
| Real | des_food_ratio_dfr | 2 | Desired food ratio |
| Real | des_ppoll_index_DPOLX | 1.2 | Desired persistent pollution index |
| Real | des_res_use_rt_DNRUR | 4.8e9 | Desired resource utilization rate |
| Real | food_short_perc_del | 2 | Food shortage perception delay |
| Real | fr_agr_inp_pers_mtl | 0.001 | Effective fraction of agricultural pollution input |
| Real | frac_res_pers_mtl | 0.02 | Effective fraction of resource utilization on pollution generation |
| Real | hlth_serv_impact_del | 20 | Health service impact delay |
| Real | income_expect_avg_time | 3 | Income expected average time |
| Real | ind_mtl_emiss_fact | 0.1 | Industrial materials emission factor |
| Real | ind_mtl_toxic_index | 10.0 | Industrial materials toxicity index |
| Real | ind_out_pc_des | 350 | Desired annual industrial per capita output |
| Real | ind_out_in_1970 | 7.9e11 | Industrial output in 1970 |
| Real | inherent_land_fert | 600 | Inherent land fertility |
| Real | labor_force_partic | 0.75 | Percentage of participating labor force |
| Real | labor_util_fr_del_time | 2 | Labor utilization fraction delay time |
| Real | land_fr_harvested | 0.7 | Land fraction harvested |
| Real | life_expect_norm | 28 | Normal life expectancy |
| Real | lifet_perc_del | 20 | Perceived life-time delay |
| Real | max_tot_fert_norm | 12 | Normal maximal total fertility |
| Real | p_avg_life_agr_inp_1 | 2 | Default average life of agricultural input |
| Real | p_avg_life_agr_inp_2 | 2.5 | Controlled average life of agricultural input |
| Real | p_avg_life_ind_cap_1 | 14 | Default average life of industrial capital |
| Real | p_avg_life_ind_cap_2 | 18 | Controlled average life of industrial capital |
| Real | p_avg_life_serv_cap_1 | 20 | Default average life of service sector capital |
| Real | p_avg_life_serv_cap_2 | 25 | Controlled average life of service sector capital |
| Real | p_fioa_cons_const_1 | 0.43 | Default fraction of industrial output allocated to consumption |
| Real | p_fioa_cons_const_2 | 0.43 | Controlled fraction of industrial output allocated to consumption |
| Real | p_ind_cap_out_ratio_1 | 3 | Default industrial capital output ratio |
| Real | p_land_yield_fact_1 | 1 | Default land yield factor |
| Real | p_nr_res_use_fact_1 | 1 | Default non-recoverable resource utilization factor |
| Real | p_ppoll_gen_fact_1 | 1 | Default persistent pollution generation factor |
| Real | p_serv_cap_out_ratio_1 | 1.0 | Default fraction of service sector output ratio |
| Real | p_serv_cap_out_ratio_2 | 1.0 | Controlled fraction of service sector output ratio |
| Real | pot_arable_land_tot | 3.2e9 | Total potential arable land |
| Real | ppoll_in_1970 | 1.36e8 | Persistent pollution in 1970 |
| Real | ppoll_trans_del | 20 | Persistent pollution transmission delay |
| Real | processing_loss | 0.1 | Processing loss |
| Real | reproductive_lifetime | 30.0 | Reproductive life time |
| Real | social_adj_del | 20 | Social adjustment delay |
| Real | social_discount | 0.07 | Social discount |
| Real | subsist_food_pc | 230 | Available per capita food |
| Real | tech_dev_del_TDD | 20 | Technology development time |
| Real | urb_ind_land_dev_time | 10 | Urban and industrial land development time |
| Real | t_air_poll_time | 4000 | Air pollution change time |
| Real | t_fcaor_time | 2002 | Year of capital allocation to resource use efficiency |
| Real | t_fert_cont_eff_time | 2002 | Year of continued fertility change |
| Real | t_ind_equil_time | 2002 | Year of industrial equilibrium |
| Real | t_land_life_time | 2002 | Land life time |
| Real | t_policy_year | 2002 | Year of policy change |
| Real | t_pop_equil_time | 4000 | Population equilibrium time |
| Real | t_zero_pop_grow_time | 2002 | Time to zero population growth |
| Real[:] | p_fr_cap_al_obt_res_2 | {1, 0.1, 0.05, 0.05, 0.05, 0.05, 0.05, 0.05, 0.05, 0.05, 0.05} | Non-renewable resource fraction remaining |
| Real[:] | p_ppoll_tech_chg_mlt | {-0.04, -0.04, 0, 0} | Persistent pollution technology change multiplier |
| Real[:] | p_res_tech_chg_mlt | {-0.04, -0.04, 0, 0} | Resource technology change multiplier |
| Real[:] | p_yield_tech_chg_mlt | {0, 0, 0.04, 0.04} | Yield technology change multiplier |
| Real | agr_inp_init | 5e9 | Initial agricultural input |
| Real | arable_land_init | 0.9e9 | Initial arable land |
| Real | industrial_capital_init | 2.1e11 | Initial industrial investment |
| Real | labor_util_fr_del_init | 1 | Initial delayed labor utilization fraction |
| Real | land_fertility_init | 600 | Initial industrial investment |
| Real | nr_resources_init | 2e12 | Initial available non-recoverable resources |
| Real | perc_food_ratio_init | 1 | Initial perceived food ratio |
| Real | pers_pollution_init | 2.5e7 | Initial persistent pollution |
| Real | pop1_init | 65e7 | Initial population 14 years and younger |
| Real | pop2_init | 70e7 | Initial population 15 to 44 years old |
| Real | pop3_init | 19e7 | Initial population 45 to 64 years old |
| Real | pop4_init | 6e7 | Initial population 65 years and older |
| Real | pot_arable_land_init | 2.3e9 | Initial potential arable land |
| Real | ppoll_tech_init | 1 | Initial persistent pollution technology change factor |
| Real | res_tech_init | 1 | Initial non-recoverable resource technology factor |
| Real | service_capital_init | 1.44e11 | Initial service sector investment |
| Real | urban_ind_land_init | 8.2e6 | Initial urban and industrial land |
| Real | yield_tech_init | 1 | Initial yield technology factor |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Real | population | Total human world population | |
| Real | food | Total annually produced food | |
| Real | industrial_output | Total annual world industrial output | |
| Real | ppoll_index | Persistent pollution index | |
| Real | nr_resources | Remaining non-recoverable natural resources | |
| Real | fioa_ind | Fraction of industrial output allocated to industrial/military complex | |
| Real | s_fioa_agr | Fraction of industrial output allocated to food production | |
| Real | s_fioa_cons | Fraction of industrial output allocated to consumption | |
| Real | s_fioa_serv | Fraction of industrial output allocated to service sector | |
| Real | s_fr_cap_al_obt_res | Fraction of capital allocated to resource use efficiency | |
| Real | life_expectancy | Life expectancy | |
| Real | food_pc | Total annual food per person | |
| Real | serv_out_pc | Total annual services per person | |
| Real | ind_out_pc | Total annual consumer goods per person | |
| Real | human_ecological_footprint | Human ecological footprint | |
| Real | human_welfare_index | Human welfare index | |
| Population_Dynamics | Population_Dynamics1 | Population dynamics | |
| Pollution_Dynamics | Pollution_Dynamics1 | Persistent pollution generation | |
| Arable_Land_Dynamics | Arable_Land_Dynamics1 | Arable land dynamics | |
| Food_Production | Food_Production1 | Food production | |
| Human_Ecological_Footprint | Human_Ecological_Footprint1 | Human ecological footprint | |
| Human_Fertility | Human_Fertility1 | Human fertility | |
| Human_Welfare_Index | Human_Welfare_Index1 | Human welfare index | |
| Industrial_Investment | Industrial_Investment1 | Industrial investment | |
| Labor_Utilization | Labor_Utilization1 | Labor utilization | |
| Land_Fertility | Land_Fertility1 | Land fertility | |
| Life_Expectancy | Life_Expectancy1 | Life expectancy | |
| NR_Resource_Utilization | NR_Resource_Utilization1 | Non-recoverable natural resource utilization | |
| Service_Sector_Investment | Service_Sector_Investment1 | Service sector investment |