Pleine, la planète? ed. by Ian Goldin (review)

This book takes up once again the problem formulated by Thomas Malthus in 1798: how far have we come in peopling the earth and is the planet overpopulated or in the process of becoming so? Malthus posited that human beings had to eat and that “the passion between the sexes” would remain nearly in the state it was at the time he was writing. From these two axioms the Reverend drew his population principle: “subsistence increases only in an arithmetical ratio” whereas “population … increases in a geometrical ratio.” It followed that “checks” were needed to maintain a reasonable balance between population and food. This principle – all Malthus did was to express it in simple, readily understandable terms – has haunted population studies to this day, as Ian Goldin notes in his introductory chapter.

That chapter and the ten that follow take up questions ranging from optimum population to health services and governance. Chapters 2 and 3 discuss ethics questions and touch on resource and economic issues. Chapters 4 and 5 are more specifically demographic. Chapters 6, 7, and 8 discuss resource availability. Chapters 9, 10, and 11 consider policy aspects and challenges at the scale of the planet, outlining some possible solutions.

Goldin, a globalization and development specialist, recalls in his introductory chapter that what is at stake in globalization is the fate of the planet as a whole, not that of any given country or region. He recalls as well that the Malthusian problem is not only a matter of quantity but also and above all quality: income growth, improvements in health and life expectancy are all factors that put pressure on the planet and what becomes of it. Technological developments make lives more complex and therefore create a need for ever-more elaborate solutions – we need to change our way of thinking, concludes the author. And in the closing chapter he formulates and works to answer four questions: What are the ethics questions involved in population growth? What is the impact of population growth on inequality and resource distribution? What is the current state of the ecosystem and how will it evolve? What should be done to halt the negative effects of population growth and control its positive effects? Given the nature of these concerns, whether or not humanity will be able to meet the challenge represented by the Malthusian problem will depend on governance. The question “Is the planet full?” is not a matter of numbers but rather determining how those numbers should be managed – management that is becoming increasingly complex in an increasingly interconnected world.

Chapter 2, by an economist, raises precisely the question in the title, combining economics and ethics approaches to answer it. The difficulty as the author sees it is to determine the optimum population, and that difficulty cannot be overcome using classic utilitarian models, which justified extreme demographic growth in terms of maximum utility even though that meant individuals living in extreme poverty. In this connection the author cites the work of the Indian economist Amartya Sen. Does our attraction to innovation and economic dynamism justify higher population levels? Measures must be taken to promote global redistribution of wealth.

For the author of Chapter 3, a philosopher, the instrumental and intrinsic benefits of further populating the planet should be measured against the costs that additional lives will create in terms of carrying capacity. Those costs constitute either “hard limits,” absolute barriers to demographic growth, or “soft limits” that take into account both technological progress and societal and behavioural change. According to this author, then, demographic pressure is malleable and may prove flexible.

Chapter 4 is by a gerontologist. Drawing on the demographic transition model, she stresses the considerable change that has occurred in parameters affecting settlement, namely in response to environmental impacts. The problems caused by high fertility are aggravated by climate change. However, the chapter is primarily a reminder of fertility-measuring indicators and offers little that is new.

Chapter 5...