By Dr. Warren M. Hern, MD, MPH, PhD


Colorado Peace Mission   Vol. 6  #5      June  1995


  A Jewish friend once told me of a bit of Talmudic wisdom: “If you want peace, work for justice.”  This is surely true, whatever the source.  But we have a new force in the world that threatens and destroys peace: uncontrolled growth of the human population.  Population growth is not such a new threat to peace: population pressure has been a source of human conflict over resources for thousands of years.  The only thing new about it is the immense, almost incomprehensible scale of the problem as it has emerged in the late 20th century.  It is no longer possible for informed people to deny the crushing effects of population growth (although some very important people vehemently deny it). 

     But consider some facts that are increasingly troubling to anyone who will examine their implications:

·        It took 3.5 million years of human evolutionary history (counting the appearance of the genus Homo) for the human population to reach 2.5 billion, which occurred in 1950.  But it took only another 35 years to reach 5.0 billion.

·        The rebate of growth of the human population has steadily increased over the past 10,000 years from an estimated 0.001% per year to a currently estimated 1.7 – 1.8% per year.  We have averaged a rate of 1.9% per year for the past 35 years, with surges of over 2.0% per year during the decades of  the 60’s and 70’s.

·        The corollary of the increasing rates of growth is that doubling times of the human population have diminished by half with the last four doublings since AD0.  It took 1650 years to go from 250 million to 500 million, 200 years to go from 500 million to 1 billion, 80 years to go from 1 billion to 2 billion (which we reached in about 1930), and only 44 years to the next doubling of 4 billion in 1974. 

·        In many parts of the world, population growth rates are increasing, not decreasing, and reaching levels as high as 3.8 – 4.0% per year.  It is not uncommon for scientists to document local population growth rates of over 4.5%, as I have in the Peruvian Amazon.  The country with the highest growth rate in Africa, until last year when the society collapsed, was Rwanda at 3.8% per year.  The country with the highest growth rate in the Western hemisphere at 3.8% per year, also a country that has teetered on the brink of total collapse, is Haiti.

·        Famine and food crises, as well as large scale epidemics, have been part of human history since the beginning of human society.  But these are now accentuated by the collapse of local and regional ecosystems.

·        The human species is the only biological organism in the history of the planet that, through its growth in numbers and elaboration of culture, has modified the planetary ecosystem and systematically brought large numbers of other species to extinction.  We are now eliminating as many as 50 to 100 species per day.


     The principal manner by which we have become the dominant species on the planet and exploiters of all ecosystems is through cultural adaptations, including social and political organization.  However, as we can see in places like Rwanda, Bosnia, the Middle East, Haiti, and downtown Los Angeles, human societies are collapsing and being devoured by permanent or sporadic total conflict.

     Political scientist Thomas Homer-Dixon has pointed out the fact that rapid population growth and the resulting pressure on increasingly scarce resources is leading directly to violent upheaval and political conflict throughout the world.  He also predicts that this trend will continue and become worse in the next century, when we will reach population levels never before experienced by the human population. 

     If we want peace, one of the most important things we can do is work toward the goals of total access to all methods of fertility control for everyone on the planet who wants them, and for other programs that contribute to the cessation of human population growth as soon as possible.  The most important programs of this kind included improved educational and economic opportunities for women everywhere.

     Unless population growth is stopped along with wiser use of the world’s resources, violent conflict will continue to increase and peace will be a poet’s dream.


    Dr. Hern is a physician in private practice as well as Associate Professor of the Department of Anthropology and Research Associate in the Environment & Behavior Program at the Institute of Behavioral Science at the University of Colorado.