Concluding Comments

When viewed from a historic perspective, see ‘demographic history, it is clear that even much smaller global populations have caused over-consumption of natural resources faster than they could be renewed. However, historic cases of over-consumption were essentially localised events, where today, the problems linked to over-consumption are global and possibly multi-faceted in scope when viewed in terms of the demographic complexity of the modern world. While the data shows that over-consumption can be mainly attributed to a relatively small percentage of the population (10-20%), it is unclear that there is any practical solution on the horizon. In 1972, the results of a computer simulation called the ‘Limits to Growth (LTG)was published, which attempted to simulate the effects of economic and  population growth when  constrained by finite resources. While a more detailed review of this work is provided via the link above, the following chart is a much simplified summary of the results defined as the ‘standard run’.

The original LTG model was designed to simulate the system dynamics of the food supply and resource production needed to keep pace with the needs of a growing world population, while trying to account for the ability of the environment to absorb and degrade the effects of pollution. In the context of a large-scale  system dynamics model, many of the contributing factors were an aggregation of many variables, such that it only attempted to reflect the probability of future trends rather than providing accurate predictions.  Even so,  the model was used to study a number of possible futures based major 5 factors:

  • World Population
  • Continued Industrialization 
  • Resulting Pollution
  • Food Production
  • Resource Depletion

For the purposes of this discussion, only the values for the ‘non-renewable resources, population and industrial output’ associated with the ‘standard run’ are shown in the chart above, which have  been normalised, such that only the general shape of the curves is important. While this model has also been the subject of much debate, subsequent 30 year and 40 year updates still suggest that the model may not be that far from the mark.  However, despite the warnings implicit in these results, it would appear that no effective action has been taken, to-date, to address the core  problems.

Why is this so and what might it tell us about the probability of any corrective action?

Well, some have argued that the model was too simplistic, such that its findings cannot be taken seriously and should therefore be ignored. However, the authors acknowledged the model’s simplifications, although in a way that suggested that the model might possibly be too optimistic:

..the LTG model is a simplification of reality, which does not distinguish among different geographic parts of the world, nor does it represent separately the rich and the poor…… there is no military capital or corruption explicitly represented in the model, because incorporating those many distinctions would not necessarily make the model better and very much harder to comprehend. This probably makes the model highly optimistic. It has no military sector to drain capital and resources from the productive economy. It has no wars to kill people, and destroy capital, nor waste lands. It has no ethnic strife, no corruption, no floods, earthquakes, nuclear accidents, or AIDS epidemics. As such, the model represents the uppermost possibilities for the ‘real’ world .

Others have argued that the model does not fully account for positive benefits of future technology. Again, the following statement taken from the 30 year update report seems to be a succinct appraisal as to why technology, in isolation, has not been the universal panacea to all the problems discussed:

“One reason technology and markets are unlikely to prevent overshoot and collapse is that technology and markets are merely tools to serve goals of society as a whole. If society’s implicit goals are to exploit nature, enrich the elites, and ignore the long term, then society will develop technologies and markets that destroy the environment, widen the gap between rich and poor, and optimize for short-term gain. In short, society develops technologies and markets that hasten a collapse instead of preventing it.”

Of course, if we were to accept some of the basic findings of this simulation model, then the debate as to whether over-population or over-consumption are the key problem may be somewhat irrelevant, if no ‘practical solution’ can be realised in the timeframe before any pending global crisis inflicts what might be a very brutal form of ‘natural selection’ . As explained in the discussion entitled the ‘Human Footprint, the global population might be roughly estimated as a function of the Earth’s biocapacity and the footprint per capita, as shown below:


Estimates currently have the average footprint to be 1.8 gha/capita, which currently requires a global biocapacity of 12 billion global hectares. However, this biocapacity is estimated to 1.5 times higher than the Earth can sustain, which might suggest that the Earth’s sustainable biocapacity is only 8 billion global hectares, Therefore, the chart below characterises a range of results that can be obtained from equation [1]:

On a very optimistic note, we might assume that the biocapacity can be increased, in a sustainable way, from 8 billion to 20 billion global hectares, while the average footprint is reduced from 1.8 gha/capita to 1 gha/capita. If so, it might suggest that a global population of 20 billion could be supported. On the hand, if the Earth’s biocapacity cannot be increased without inflicting yet more environmental damage and the average footprint increases to 4 gha/capita, as more people aspire to emulate the consumption of the top 10%, the global population might fall towards 2 billion. However, according to the LTG model, ‘today’s speculation’ will be ‘ tomorrow’s reality’ for future generations by the end of this century.

And how many of today’s decision-makers will be alive by then?

At the beginning of this section of discussions, the following issues were tabled as possible topics of discussion that might influence both the growth in population and resource consumption over the next century:

  • Population and resource requirements
  • Wealth distribution and demands for better living standards
  • Economic impacts of smaller populations
  • Ideological tensions, political, economical and theological.
  • Population growth surplus to requirements

By large, most of these topics have been touched upon throughout the various discussions with the possible exception of the issues surrounding the last bullet. Today, we live in a world that demands a certain level of ‘political correctness’ and while this is not a bad thing, it can often suppress debate of important issues. So, in the context of political correctness, the following question may appear inappropriate:

What percentage of the global population is surplus to requirements?

This question is only being tabled at this point, but as you consider this question in the privacy of your own thoughts, it is first worth remembering that it is hypothetical in scope. This said, you are being asked to take into consideration all of the possible implications outlined in the previous discussions. For the suggestion is that over-population in conjunction with over-consumption, driven by an economic system that appears to be predicated on never-ending growth, is simply unsustainable. We might also have to take into consideration the demographic complexity of the modern world, which may make it impossible for any sort of ‘political consensus’ to take meaningful, let alone effective, corrective action on a global scale before it is too late. If so, then only feedback in the system itself will cause change. 

What sort of feedback are we talking about?

The system dynamics of the ‘limits to growth’ model essentially reflects the interaction and feedback between the five variables modelled, i.e. global population, continued industrialization, resulting pollution, food production and resource depletion. Based on the shape of the curves in the initial LTG chart above, it would seem that the net result of the feedback between these variables is negative and results in a falling global population and industrial output aggravated by the increasing depletion of natural resources. However, these  are the results of a simplified model, which could never hope to reflect the full demographic complexity implicit in the distribution of population, natural resources, cultures and political systems of some 190+ countries around the world. However, despite all this apparent complexity, it might not be unreasonable to assume that wealthy countries may be better positioned to protect their population from the trends suggested by the LTG model than poorer countries. If so, the following table might provide some indication of the ‘winners and losers’ in any global downturn:

Country GDP
Country GDP
1 US $16,768,100   185  Comoros $616
2  China $9,181,204   186  Dominica $499
3  Japan $4,898,532   187  Tonga $465
4  Germany $3,730,261   188  Micronesia $327
5 UK $2,678,455   189  São Tomé $261
6  France $2,267,456   190  Palau $213
7  Brazil $2,243,854   191  Marshall Islands $198
8  Italy $2,149,485   192  Kiribati $176
9  Russia $2,096,774   193  Nauru $121
10  India $1,937,797   194  Tuvalu $40

Clearly, there is a huge disparity between the GDP of the top ten countries in comparison to the bottom ten, which might reflect their ability to survive a pending global downturn. We might also see this trend in the military spending of some countries, although it less clear that this will be such a key factor unless the rule of international law collapses.

Country Military
1 US 640.0 3.8
2 China 188.0 2.0
3 Russia 87.8 4.1
4 Saudi Arabia 67.0 9.3
5 France 61.2 2.2
6 UK 57.9 2.3
7 Germany 48.8 1.4
8 Japan 48.6 1.0
9 India 47.4 2.5
10 South Korea 33.9 2.8

We might also want to consider the footprint and biocapacity data, but now weighted by population as in the table below. While the overshoot value of China, India and US is not that dissimilar, there is a large difference between the footprint per capita figures for China and India in comparison to the US. Of course, if the large populations in China and India aspire to a better standard of living, then their comparatively low footprint figures could increase dramatically over the coming decades. If so, then the current estimated biocapacity for these countries will have to be increased by a similar amount, if the overshoot is not to rise at an alarming rate. If this does happen, the average global footprint of 1.8 gha/capita will increase, where the consequences have been outlined in the chart above.

Country Population
 China 1336.55 2.21 2953.8 1309.8 2.26
 India 1164.67 0.91 1059.8 594.0 1.78
US 310 8 2480.0 1199.7 2.07
 Indonesia 224.67 1.21 271.9 303.3 0.90
 Brazil 190.12 2.91 553.2 1707.3 0.32
 Pakistan 173.18 0.77 133.3 74.5 1.79
 Bangladesh 157.75 0.62 97.8 59.9 1.63
 Nigeria 147.72 1.44 212.7 165.4 1.29
 Russia 141.94 4.41 626.0 816.2 0.77
 Japan 127.4 4.73 602.6 76.4 7.88

With going into further comparative details, it might simply be recognised that some countries may be much better placed to ‘weather any coming storms’ . Of course, it might also be recognised that the poorer section of society, even in the developed countries, may still be more exposed to any form of global downturn. As such, we are forced back to the unsettling question tabled earlier:

What percentage of the global population is surplus to requirements?

If, as suggested, the world remains effectively powerless or unwilling to change the demands it is placing on planet Earth, then some form of ‘natural selection’ will simply reduce over-population and/or over-consumption for us. However, the question above is NOT intended as some subliminal argument for culling off certain sections of the global population, but rather it has more to do with what humanity aspires to become. The following quote by Carl Jung is used on the top page of this website because it seems to encapsulate the idea that mere survival is not enough:

As far as we can discern,
the sole purpose of human existence is to kindle
a light in the darkness of mere being.

So, at this point in time, it is unclear how, or even if, humanity  will survive long into the future. However, all the evidence seems to suggest that it cannot continue along its current path for much longer. As such, this review of population versus consumption will, again, end on the following quote and the link to the wider debate about humanity’s long-term future.

Evolution is an on-going process.
As such, humanity is a transitional result.


Note: As this website does not pretend to have any authority of the issues discussed, feedback on any of the points or arguments raised would be welcomed. In order to facilitate any such review, a PDF version of the discussions in this section has been created that might help wider distribution.