In 1992, 68 percent of Americans believed population growth to be a pressing problem, according to public opinion polls from that year. In 2000, that number had declined to just eight percent of Americans and, most telling of all, the topic does not even appear in the most recent polls. Now a review of nearly 200 research articles reveals how population growth is being downplayed and trivialized by scientists despite its fundamental and negative role in the areas of employment, public debt, human welfare, extinction of species, and climate change. “More than one billion people live in extreme poverty and hunger, and ecosystems are losing species at rates only seen in previous mass extinction events,” wrote Camilo Mora, assistant professor of Geography in the College of Social Sciences at University of Hawaii at Manoa. “The issue of population growth has been downplayed and trivialized among scientific fields, which may in part account for the reduced public interest in the issue and in turn the limited will for policy action.” His sobering review appears in Ecology and Society.

Mora began his study by examining recent literature highlighting the key role of overpopulation in several pressing social and environmental issues. The majority of the case studies he investigated — more than 70 percent — had been published in the last decade. In particular, he focused on how the issue was addressed in reports on climate change, employment, public debt, human welfare, and extinction of species.

Again and again he found the topic of overpopulation critically underplayed. Net production of greenhouse gases, for instance, may be equal in developed and developing nations due to heavy consumption patterns in the former and large population growth in the latter. Yet the Intergovernmental Panel on Climate Change does not even refer or address the issue of population growth, family planning, or any related matter. Some of the most authoritative reports on food security, which depends, in part, on how many people there are to feed, similarly lack any reference to overpopulation. Finally, population growth is marginalized, by Mora’s account, in key reports about improving human welfare and health care systems.

With evidence mounting “that overpopulation is a common denominator” to many environmental and socioeconomic issues, “tackling population growth could deliver not only beneficial but also long-term resolutions to a wide range of pressing issues,” Mora wrote. Among the simple solutions that would help keep a growing populace in check he suggests sex education, empowering women, providing affordable family planning, revisiting subsidies that promote natality (such as tax breaks), and highlighting the economic cost for the future success of children.

Population stabilization, Mora noted, is only achieved when the natality rate is equal to the mortality rate. For this reason, the target that is often suggested is 2.1 children per woman (one child to replace the mother, one to replace the father, and 0.1 to account for child mortality). Unfortunately, increasing life expectancy and early reproduction have created an overlap of generations, increasing the size of the general population even when growth rates are kept at replacement levels. Realistically, then, population stabilization may only be achieved at a rate of one child per woman. To change global behavior “will entail increasing public awareness on the issue; and for this, we need greater courage from scientists to take a public stand on the issue of population growth,” Mora concluded.

Source: Mora C. Revisiting the Environmental and Socioeconomic Effects of Population Growth: a Fundamental but Fading Issue in Modern Scientific, Public, and Political Circles. Ecology and Society. 2014.