Human population and the global environment.

| October 24, 2017 | Leave a Comment

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Media Type: Article - Foundational

Year of Publication: 1974

Author(s): Holdren JP, Ehrlich PR.

Journal: American Scientist

Volume: 62

Pages: 282-292

Categories: ,

In this paper, Holdren and Ehrlich tackle the misconceptions they feel are both dangerous and common among decision makers:

“(1) the absolute size and rate of growth of the human population and has little or no relationship to the rapidly escalating ecological problems facing mankind;

(2) environmental degradation consists primarily of ‘pollution,’ which is perceived as a local and reversible phenomenon or concern mainly for its obvious and immediate effects on human health; and

(3) science and technology can make possible the long continuation of rapid growth in civilization’s consumption of natural resources” (p282).

In doing so, the authors classify environmental problems according to the damage they pose to human beings as either “direct assaults” or “indirect effects”. “Indirect effects” largely consist of the environmental problems that are posed to undermine the functioning of natural systems humans rely on. Though most attention at the time (1974) focused on minimizing “direct assaults” such as polluted water sources, the authors argue, “The most serious threats of all, however, may well prove to be the indirect ones generated by mankind’s disruption of the functioning of the natural environment” (p282). They support this argument by briefly reviewing “public-service” functions of the global environment and establishing that the operations of natural biological processes are both irreplaceable and indispensable, or non-substitutable. Unfortunately, through examples of desertification and deforestation, Holdren and Ehrlich demonstrate that civilization’s aim “to manage ecosystem in such a way as to maximise productivity,” is incompatible with “nature’s” tendency “to [manage] ecosystems in such a way as to maximize stability” (p287). This tendency is causing mankind, as a global and biological force, to become “comparable and even exceeding many natural processes,” pushing systems away from stability (p287). The scale of the resulting environmental deterioration is explained by the authors with the equation:

“Environmental disruption = population x consumption per person x damage per unit of consumption”  

–which is the basis for the I=PAT equation, also attributed to the authors. Thus, the population size, consumption and effect per unit of consumption interact multiplicatively to determine the extent of environmental disruption. The authors clarify, “For problems described by multiplicative relations like the one just given, no factor can be considered unimportant” (p288). Thus, actions taken to reduce the environmental disruption caused by humans “should include measures to slow the growth of the global population to zero as rapidly as possible. Success in this endeavor is a necessary but not sufficient condition for achieving a prosperous yet environmentally sustainable civilization” (p291). This article provides critical background on how human population size is considered to interact with consumption, and the importance of addressing both in efforts to reduce environmental disruption.

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  • Greeley Miklashek

    We have an evolved neuro-endocrine population regulation mechanism, which is activated by population density stress. J. J. Christian described it in lab animals back in the 1960’s and his publications are free on the net. I recommend that the above noted equation for environmental disruption be revised to: Environmental disruption= Population/Population Density StressXConsumption Per PersonXDamage Per Unit of Consumption. The true cause of “environmental disruption” are our technological “advances” that have allowed us to escape the obvious “limitations to increase” described by Malthus and Darwin: war, famine, “misery and vice”, as well as our altruism driven medical and public health efforts to keep us all alive. Educating women, free access to birth control, and the resultant one-child families will bring our numbers back down to a sustainable 2.5 billion world-wide by 2,100. Over-consumption by Westerners is a moral issue. Good luck with that one! Only the wide dissemination of the health destroying effects of population density stress, which includes ALL of the top ten “diseases of civilization”, can force us to make such a “moral” choice. Stress R Us

    • FiendishGOPlardass

      according to alot of people eg many Californians, or New york city dwellers, think traffic jams and a 15 billion pop. are just engineering challenges— water pipes etc.

      • Greeley Miklashek

        Population density stress is the root cause of ALL of our “diseases f civilization”, almost none of which are found among contemporary hunter-gatherer clans living in their traditional manner. Got an answer for that one? Why is nobody else asking these questions? Google “Stress R Us” for the details.