Demorphic Growth Principle and Energy Slave

The environment nurtures us in the best way it can. It supplies us with things without which we would fall in an existential crisis and perish in a matter of time. Though these words we all understand make the importance of environment clear, it is us and our activities which are damaging our mother nature. And unsurprisingly in a matter of no time, we will face the rage of the nature upon us.

Today we are presenting you with an article that might help you understand the formula behind this environmental crisis and puzzle you with a new term called ‘Energy Slave’.

Let’e begin……………

JR Vallentyne, a Canadian paleo-limnologist revealed that impending environmental crisis we are facing results from two types of growths:
-population growth and
-technological growth
both directly in sense of increased per head production and consumption and indirectly in that technology furthered growth of population and urbanization.

Concept of growth encompassing combined effects of population in biological sense and of production, consumption in technological sense has been termed Demorpha.

Per capita use of energy good index of resource utilization called D-index = T/P, where T = technological growth, P = physiological metabolism.

For utilization of manpower 0.15 KW energy or 0.2 PS used. A motor car of 65 PS used by that person requires 47.5 KW energy i.e., 325 times more. Here D=325.

Energy Slaves

An energy slave is that quantity of energy (ability to do work) which, when used to construct and drive non-human infrastructure (machines, roads, power grids, fuel etc.) replaces a unit of human labor (actual work).

For example, imagine that you are riding a car from Basabo to Curzon Hall. That car uses some power in Horse Power (HP) unit deriving from its fuel used. Imagine… instead of fuel a definite number of horses are pushing the car. Now again in stead of the horses imagine people pushing the car for you. Apparently, this amount of people is called the energy slave you are using to ride your car.

The Energy Slaves

An energy slave does the work of a person, through the consumption of energy in the non-human infrastructure such as a motor cycle.

An energy slave is used to compare the productivity of a person (such as energy to move to a place) and the energy that would be required to produce that work in the modern, oil fuelled industrial economy (moving in motorcycle).

Formally, one energy slave produces one unit of human labor (follow the last example) through the non-human tools and energy supplied by the industrial economy, and therefore 1 ES times a constant that converts to work accomplished = 1 human labor unit.

Before you get puzzled anymore by my …please visit this link below and take your time to understand the energy slave cartoons.

From D-index, demand of energy for any country can be obtained. This figure multiplied by population gives number of Energy Slaves.

as without bread and water no life can be sustained and any machine becomes invalid without energy, based on this concept of Energy Slave applied.

e.g., energy from one MT coal  equivalent can rare 8.1 non technological human being equal to one year’s Energy Slave.

In reality, for survival upon earth, every man requires both P and T.

Therefore, summation of P and T indicates energy demand by every individual. D-unit = (P+T).

D-index and resource consumption

D-index and D-unit of some developed and developing nations of world calculated according to number of Homo sapiens for 1973.

Country Area (km2) D-index P (in million) D-unit (million)
USA 9.36 97 210 20400
Canada 9.97 91 22 2000
FRG 0.25 47 62 2900
UK 0.24 47 56 2700
China 9.56 5 814 4700
Mexico 1.97 11 54 650
Brazil 8.51 5 101 570

Conclusion with facts

  • Increasing trend in energy consumption and resource utilization observed in densely populated China, Mexico, Brazil are creating pressure on freshwater resource.
  • Developed nations, though their energy consumption and resource utilization higher are making no significant changes in D-index because of lower birth rate.
  • Massive industrialization in developing nations having higher birth rate will create serious pressure upon resources.
  • D-index of Myanmar, Nepal and Bangladesh is <1.
  • For India and Pakistan it is 1-2.


  1. Caplow, Theodore; Hicks, Louis; Wattenberg, Ben J. (2001). The first measured century: an illustrated guide to trends in America, 1900-2000
  2. Wikipedia (no other sources were mentioned)
  3. Presentation by our beloved, esteemed and internationally recognized limnologist Prof. Moniruzzaman, University of Dhaka.


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About Abulais Shomrat

Abulais Shomrat
Currently in 4th year (Hons) in Department of Botany, University of Dhaka. Planning to have multiple careers one by one but promised to be with 'Plantlet' as long as it's primary stage remains unfinished.

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