At long last, and possibly too late, people are beginning once again to realize that the numbers of people themselves constitute a threat to civilization. However, despite that recognition, many of a new flood of articles clearly demonstrate the continuing failure to understand the situation, even among those who ought to know better. Some of the more prominent errors are that consumption is the problem, not population; that the only difficulty is finding ways to feed an additional 2.5 billion people in the next 35 years; that a spontaneous “demographic transition” will save humanity by producing a stable population; and, of course the old bromide that human ingenuity will develop magical technologies permitting the population to grow forever.
Typical of a most basic error is the analysis of Naomi Klein, who has written an important book, This Changes Everything: Capitalism vs. The Climate that tries to tie the climate crisis to the catastrophic failure of neoliberal capitalism. Sadly, as a latecomer to the climate wars, she seems unaware of the literature and many critical issues, and makes the Pearcian mistake of asserting that the problem is not population growth but consumption by the rich. She correctly emphasizes the lethal role of unrestrained capitalism, but ignores the other dimensions of the environmental threats to sustainability, such as the loss of biodiversity and natural capital, decay of the epidemiological environment, and the true scale of the toxification of Earth, all driven and exacerbated by human population growth. Like too many commentators, Klein fails to show the historical or ecological context that could give perspective to her thesis.
Amazingly, she quotes a statement that the first industrial revolution’s contribution of greenhouse gases was a “drop in bucket” compared to present contributions made by previously poor nations such as China and India as they struggle to emulate the Victorian industrial revolution, apparently not realizing that a sevenfold expansion of the global population was an important factor in the difference. Strangely, Klein also seems aware (at least in the energy sector) that the low-hanging fruit is long gone, but fails to realize how much the decline in both quantity and quality of resources also exists in other sectors, and what this implies for a still-exploding human population. She apparently missed the research  on the greenhouse gas emissions impact of childbearing, or even of IPAT, or our article “Too many rich folks,” both part of a campaign to convince people that the population problem is not just one of too many poor people. In short, while Klein is great at exposing the delusions of the climate deniers and “big green,” she herself misses the dimensions of the environmental crisis and seems to think it can be solved without dealing with overpopulation “simply” by changing the economic and political system from the bottom up to allow a series of technofixes.
Total revision of the economic system and power structure and a redistribution of wealth and opportunity are clearly necessary but equally clearly insufficient to achieve sustainability and a decent life for all, even with today’s population, let alone billions more. It’s a pity someone as smart and articulate as Klein has failed to grasp that basic fact. But so have many other intellectual leaders, from Fred Pearce to Paul Krugman. Indeed while perpetual growth of population and consumption are generally expected by run-of-the-mill economists (the good ones  know better), the Wall Street Journal editorial page community at least have the excuse of near non-existent training in how the biophysical world really works . But how does one explain the staff of Science magazine, one of the top scientific journals in the world, writing an introduction to an issue on population, including?
“Today these demographic patterns spark concerns, not of a single explosion, but of “cluster bombs” in rapidly growing countries such as Nigeria and Pakistan, which are hobbled by poor governance and limited schooling capacity and already have huge numbers of poorly educated young adults without job prospects.”
It is a disgrace that Science staff is apparently unaware of the many global environmental problems where global overpopulation and continued population growth and overconsumption by the rich remain major drivers. But it’s just one of many disgraces driving civilization toward the brink.
 E.g., Murtaugh PA, Schlax MG. 2009. Reproduction and the carbon legacies of individuals. Global Environmental Change 19: 14–20.
 such as Partha Dasgupta, Steve Polasky, James Blignaut, Quentin Grafton, Tom Kompas, Ken Arrow, Herman Daly, Larry Goulder, Joe Stiglitz, Karl Goran Mäler, Charles Perrings, and many (but not enough) others
 Colander, D & Klamer, A. The making of an economist. Journal of Economic Perspectives 1, 95-111 (1987).
 Chin, G, Marathe, T & Roberts, L. Population: doom or vroom. Science 333, 539 (2011)
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