modelScenario_9

Combining the measures of Scenarios #6 and #8

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:

  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 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

TypeNameDefaultDescription
Realagr_mtl_toxic_index1Agricultural materials toxicity index
Realassim_half_life_19701.5Pollution assimilation half life in 1970
Realavg_life_land_norm1000Normal life span of land
Realdes_compl_fam_size_norm3.8Desired normal complete family size
Realdes_food_ratio_dfr2Desired food ratio
Realdes_ppoll_index_DPOLX1.2Desired persistent pollution index
Realdes_res_use_rt_DNRUR4.8e9Desired resource utilization rate
Realfood_short_perc_del2Food shortage perception delay
Realfr_agr_inp_pers_mtl0.001Effective fraction of agricultural pollution input
Realfrac_res_pers_mtl0.02Effective fraction of resource utilization on pollution generation
Realhlth_serv_impact_del20Health service impact delay
Realincome_expect_avg_time3Income expected average time
Realind_mtl_emiss_fact0.1Industrial materials emission factor
Realind_mtl_toxic_index10.0Industrial materials toxicity index
Realind_out_pc_des350Desired annual industrial per capita output
Realind_out_in_19707.9e11Industrial output in 1970
Realinherent_land_fert600Inherent land fertility
Reallabor_force_partic0.75Percentage of participating labor force
Reallabor_util_fr_del_time2Labor utilization fraction delay time
Realland_fr_harvested0.7Land fraction harvested
Reallife_expect_norm28Normal life expectancy
Reallifet_perc_del20Perceived life-time delay
Realmax_tot_fert_norm12Normal maximal total fertility
Realp_avg_life_agr_inp_12Default average life of agricultural input
Realp_avg_life_agr_inp_22.5Controlled average life of agricultural input
Realp_avg_life_ind_cap_114Default average life of industrial capital
Realp_avg_life_ind_cap_218Controlled average life of industrial capital
Realp_avg_life_serv_cap_120Default average life of service sector capital
Realp_avg_life_serv_cap_225Controlled average life of service sector capital
Realp_fioa_cons_const_10.43Default fraction of industrial output allocated to consumption
Realp_fioa_cons_const_20.43Controlled fraction of industrial output allocated to consumption
Realp_ind_cap_out_ratio_13Default industrial capital output ratio
Realp_land_yield_fact_11Default land yield factor
Realp_nr_res_use_fact_11Default non-recoverable resource utilization factor
Realp_ppoll_gen_fact_11Default persistent pollution generation factor
Realp_serv_cap_out_ratio_11.0Default fraction of service sector output ratio
Realp_serv_cap_out_ratio_21.0Controlled fraction of service sector output ratio
Realpot_arable_land_tot3.2e9Total potential arable land
Realppoll_in_19701.36e8Persistent pollution in 1970
Realppoll_trans_del20Persistent pollution transmission delay
Realprocessing_loss0.1Processing loss
Realreproductive_lifetime30.0Reproductive life time
Realsocial_adj_del20Social adjustment delay
Realsocial_discount0.07Social discount
Realsubsist_food_pc230Available per capita food
Realtech_dev_del_TDD20Technology development time
Realurb_ind_land_dev_time10Urban and industrial land development time
Realt_air_poll_time4000Air pollution change time
Realt_fcaor_time2002Year of capital allocation to resource use efficiency
Realt_fert_cont_eff_time2002Year of continued fertility change
Realt_ind_equil_time2002Year of industrial equilibrium
Realt_land_life_time2002Land life time
Realt_policy_year2002Year of policy change
Realt_pop_equil_time4000Population equilibrium time
Realt_zero_pop_grow_time2002Time 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
Realagr_inp_init5e9Initial agricultural input
Realarable_land_init0.9e9Initial arable land
Realindustrial_capital_init2.1e11Initial industrial investment
Reallabor_util_fr_del_init1Initial delayed labor utilization fraction
Realland_fertility_init600Initial industrial investment
Realnr_resources_init2e12Initial available non-recoverable resources
Realperc_food_ratio_init1Initial perceived food ratio
Realpers_pollution_init2.5e7Initial persistent pollution
Realpop1_init65e7Initial population 14 years and younger
Realpop2_init70e7Initial population 15 to 44 years old
Realpop3_init19e7Initial population 45 to 64 years old
Realpop4_init6e7Initial population 65 years and older
Realpot_arable_land_init2.3e9Initial potential arable land
Realppoll_tech_init1Initial persistent pollution technology change factor
Realres_tech_init1Initial non-recoverable resource technology factor
Realservice_capital_init1.44e11Initial service sector investment
Realurban_ind_land_init8.2e6Initial urban and industrial land
Realyield_tech_init1Initial yield technology factor

Components

TypeNameDefaultDescription
RealpopulationTotal human world population
RealfoodTotal annually produced food
Realindustrial_outputTotal annual world industrial output
Realppoll_indexPersistent pollution index
Realnr_resourcesRemaining non-recoverable natural resources
Realfioa_indFraction of industrial output allocated to industrial/military complex
Reals_fioa_agrFraction of industrial output allocated to food production
Reals_fioa_consFraction of industrial output allocated to consumption
Reals_fioa_servFraction of industrial output allocated to service sector
Reals_fr_cap_al_obt_resFraction of capital allocated to resource use efficiency
Reallife_expectancyLife expectancy
Realfood_pcTotal annual food per person
Realserv_out_pcTotal annual services per person
Realind_out_pcTotal annual consumer goods per person
Realhuman_ecological_footprintHuman ecological footprint
Realhuman_welfare_indexHuman welfare index
Population_DynamicsPopulation_Dynamics1Population dynamics
Pollution_DynamicsPollution_Dynamics1Persistent pollution generation
Arable_Land_DynamicsArable_Land_Dynamics1Arable land dynamics
Food_ProductionFood_Production1Food production
Human_Ecological_FootprintHuman_Ecological_Footprint1Human ecological footprint
Human_FertilityHuman_Fertility1Human fertility
Human_Welfare_IndexHuman_Welfare_Index1Human welfare index
Industrial_InvestmentIndustrial_Investment1Industrial investment
Labor_UtilizationLabor_Utilization1Labor utilization
Land_FertilityLand_Fertility1Land fertility
Life_ExpectancyLife_Expectancy1Life expectancy
NR_Resource_UtilizationNR_Resource_Utilization1Non-recoverable natural resource utilization
Service_Sector_InvestmentService_Sector_Investment1Service sector investment