Worse than Foreseen by
(even if the living do not outnumber the dead)
William R. Catton, Jr.,
Professor Emeritus, Washington State University
In the decade just after World War 2, the ideas of Thomas Robert Malthus made a comeback. Becoming acutely aware of rapid population increase and degradation of environments, we learned to speak of a "population explosion." A rumor circulated that there might be more humans alive in our time than the sum of all past populations. Although the rumor was mathematically incorrect, it expressed a valid concern.
If descendants of the 950 million contemporaries of Malthus in 1798 had continued doubling every 25 years (as he reported the people in England's colonies in America had been doing), there would be today 242 billion people on this planet. That would be more than the total of all past human births. 
The present world population of 6 billion is only two and a half percent of that 242 billion. World population has not doubled eight times. It has "only" doubled two and two-thirds times in the eight quarter-centuries since Malthus published his Essay on the Principle of Population. This reduced number of doublings shows how important it was to point out, as Malthus did, factors that restrain population increase.
Even if, statistically, there are not "more humans alive than dead," the more fundamental point conveyed by that inaccurate aphorism is well taken. Despite the Malthusian checks on population growth, the world is today burdened with a prodigiously huge human load.
We need to realize the "load" with which we humans burden the planet's ecosystems consists of more than just a population number. People living by different cultures not only reproduce at different rates; they impose very different per capita ecological impacts. Culture includes a population's technology and people's ways of organizing themselves. Each of us living in a "developed" country (i.e., industrialized far beyond anything conceivable to Malthus) has an enormously greater resource appetite and environmental impact than does each resident of a so-called "developing" country. For our grossly unsustainable manner of living, 6 billion is far too many.
Over all previous time, calculated estimates show that actually up to 20 times that many people were born and have died.  But the per capita demands and impacts of most of them were far less than ours are today. So, given our prodigal way of living, if one of every 20 people who have ever lived are living now, this is in itself a fact that ought to impress us no less than the spurious "more humans alive than dead" claim.
Malthus, were he among us today, would surely agree -- because it matters how we live. The very technological progress cited by those who imagine the warnings of Malthus have been rendered obsolete has actually intensified the problem he was trying to illuminate -- the problem of a human load outgrowing their environment's carrying capacity.
In recognition of our voracious appetites for non-renewable resources, I have proposed the term "Homo colossus" to designate modern humans equipped with today's technology and organization. Per capita energy use can serve as a reasonable index of the extent to which we are colossal.  During
those same two centuries since Malthus wrote his essay, the world average per capita energy use more than doubled, and in America it doubled four times! Depending on just what threshold we require for applying the label, it could well be true that there are more members of Homo colossus living than dead, even if that is not so for non-colossal Homo sapiens.
For too long too many have imagined that all 6 billion Homo sapiens (or more yet in the future) could aspire to become colossal. Even the United Nations World Commission on Environment and Development (the Brundtland Commission) advocated achieving this by accelerating economic growth everywhere, to bring living standards in the developing countries up to those of industrial nations. But the Commission seemed oblivious to the fact this would require several additional Earths to provide the needed resources and absorb the end-products of so much Homo colossus metabolism. 
If, as is increasingly being argued, we colossal modern humans have overshot global carrying capacity, a monumental downsizing episode lies ahead. Can we yet choose whether it will be a downsizing of prodigal life-styles rather than a downsizing of population numbers? That is the issue modern Malthusians are striving to bring to public attention.
-  For an early estimate of the total number of human babies ever born, see Cook, Robert C. "How Many People Have Ever Lived On Earth." Population Bulletin, 18 (February 1962):1-19.
-  See sources cited in Weeks, John R. 1989. Population: An Introduction to Concepts and Issues (4th edition). Belmont, CA: Wadsworth Publishing Co., pp. 54-55.
-  With regard to the devastating impact of our own species upon the world on which we must live, see Chapter 6 (especially the presentation of the I=PAT formula, pp. 132-134) in Ehrlich, Paul R., and Anne H. Ehrlich. 1990. The Population Explosion. New York: Simon & Schuster. In my book (Catton, William R. Jr. 1980. Overshoot: The Ecological Basis of Revolutionary Change, Urbana: University of Illinois Press) I developed a similar perspective -- but without the formula.
-  See, for example, pp. 12-16 in Wackernagel, Mathis, and William Rees. 1996. Our Ecological Footprint. Gabriola Island, B.C.: New Society Publishers.
-  See not only ibid., but also Postel, Sandra, "Carrying Capacity: Earth's Bottom Line." pp. 3-21 in Lester R. Brown, et al. 1994. State of the World 1994. New York: W. W. Norton.; and see Appendix 6 in Cohen, Joel E. 1995. How Many People Can the Earth Support? New York: W. W. Norton.