Population-Consumption Update 2010
NOTE: For full projections, see the current projections page.
Three more years of population data hasn't appreciably altered the projections of the Population-Consumption model; the world's population is still expected to peak before 2030 and then rapidly crash. The same prescription for avoiding it holds: increase the fraction of consumed mass that is renewable or reusable to nearly 100% by the end of this century.
Adjusting the numbers used in the model to better match the 2010 population, the population peak shifts either slightly (from 2022 to 2024 - v1 to v3 below) or occurs in 2014 (see v2). In the case of the shift to 2024, one of the coefficients in the model was adjusted, changing the overall growth rate and increasing the amount of difference (error) from previous population values. For the shift to 2014, the amount of resources available was reduced exponentially, with the largest amount of change occurring recently (this result can also be achieved by decreasing the total amount of resources).
The 2014 peak may be an example of the trivial case, since the population for any year can be matched by changing the amount of resources available. For example, the population in 2000 can be best matched by a positive resource growth rate, yielding a totally unrealistic population peak at 15.8 billion people in 2055 as well as more error in projected population from 2000 to 2010.
Interestingly, the closest match to the recent population numbers comes from an earlier incarnation of the model using the global ecological footprint (GEF), perhaps due to the limited time interval used for the curve fit (1961-2005). That model projects a population peak by 2035 and a drop-off that mirrors the historical increase in population.
No Change
Following are population projections. Roll over the graph with your mouse to see a closeup.
Following is the model's error for historical population. Roll over the graph with your mouse to see a closeup.
Increasing Capacity/Consumption (Start in 2012)
Following are population projections.
Following are projections of the ratio of capacity to consumption.
Following are the model variables for each version, where Consumption = A*(r2/r1)^F*t^(B*EXP(C*t^D+E*t^(D-1))), r1 is the previous year's resources (lb), r2 is this year's resources, and t is the number of years since year zero (when the Starting Resources applied).
v1
v2
v3
Starting Resources:
1.15E+15
1.15E+15
1.15E+15
Starting Population:
2.51E+08
2.51E+08
2.51E+08
A:
2.51E+10
2.51E+10
2.51E+10
B:
4.98E-05
4.98E-05
4.92E-05
C:
1.30E-03
1.30E-03
1.30E-03
D:
1.16E+00
1.16E+00
1.16E+00
E:
2.60E-01
2.60E-01
2.60E-01
F:
1.00E+00
1.00E+00
1.00E+00
Resource Growth Rate:
0.00E+00
-1.26E-04
0.00E+00
Max. Resources:
2.41E+19
2.41E+19
2.41E+19
Capacity:
0.00E+00
0.00E+00
0.00E+00
Cap/Consump. Growth Rate:
5.80E-02
5.30E-02
4.90E-02
Growth Start Year:
2012
2012
2012
© Copyright 2010-2011 Bradley Jarvis. All rights reserved.
