1This 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.
2That 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.
3Goldin, 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.
4Chapter 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.
5For 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.
6Chapter 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.
7Chapter 5, by the Secretary General of The Club of Rome, demonstrates how the concept of “overshoot” – “the notion that human population could exceed the environmental carrying capacity of the earth” – brought about new thinking on sustainable development and the consequences of perpetuating standard operating modes or “business as usual.” The disadvantages of modern consumption practices might be overcome by way of a more systemic paradigm that would no longer give absolute priority to the goal of increasing GDP. To achieve this end, the author recommends returning to the moral philosophy that presided over early economic history, in which society laid down the bases for human interaction and spirituality shaped people’s attitudes and values and provided the foundations for a universal code of ethics.
8Chapter 6, by a zoologist, critically analyses the Malthusian problem from a Boserupian standpoint. The impact of demographic growth on the world’s food system is already considerable and can only increase; meanwhile the world is suffering from obesity, malnutrition and starvation all at once. The instability caused by this pair of constraints is aggravated by the nutritional transition, wherein rising global wealth is forcing the poor to adopt a more varied diet. In order for stomachs to be filled on a full planet, food production must be intensified, diets modified, and food waste reduced. This is once again a matter for governance, the position argued by the editor in the concluding chapter.
9The climatologist who wrote Chapter 7 explores the implications of continued population growth for water supply, particularly in connection with climate change. Whereas overall demand for water is rising sharply, per capita demand is falling due to changes in behaviour and government regulations. Desalinization techniques might ensure a sufficient water supply for future generations, despite population growth.
10Chapter 8, by a professor of ecosystem science, focuses on the factors that determine human food and water needs. For the author, humanity alone has a “social metabolism”: it consumes and transforms energy at levels well beyond its natural needs. The planet is therefore the theatre of a permanent conflict between metabolic limitation and innovation. The challenge, then, is to innovate in the areas of technology and governance.
11The author of Chapter 9, a public health professor, discusses rising health service costs, due in large part to “global killers” such as tuberculosis, malaria and HIV-AIDS. But these diseases also create challenges in a context of population growth and climate change conducive to pandemics. The author has harsh words for the oligopolistic behaviour of the pharmaceutical industry and recommends alternative health service models that would combine cost-reduction and efficiency.
12Chapter 10, by the director of the Natural Environmental Research Council, discusses human needs for mineral resources. The author risks a prediction on how population growth will impact on those resources. They are of course plentiful, but like all actions that aim to control climate change, mineral resource extraction will always itself consume great quantities of energy. Last, population growth will increase demand for those resources and could prove cataclysmic. The author recommends inventing new methods for using, treating and reusing these materials and products.
13According to the editor, this collective work makes three contributions. First, a long awaited updating of the Malthusian problem, i.e., the debate on population growth. Second, an original holistic – and not exclusively demographic – approach (the latter would only discuss the planet’s carrying capacity) that combines different perspectives. Last, accounts that cite the latest scientific explanations, not available in the preceding decades.
14The book as a whole does fulfil these claims. While the subject is the Malthusian problem, nearly all chapters encompass the parameters of climate change and the need for global governance. Those factors, especially climate change, become the point around which all thinking turns; rigorous demographic analysis is missing in some cases or granted only secondary importance; this seems the price to pay for a holistic approach endorsed by all contributors. What demographic analysis there is fluctuates between elementary and naïve, particularly in Chapter 4. These reservations aside, the book is easy to read, well documented, and offers a useful index. I would recommend reading selectively in it, if only to keep abreast of recent developments in English-language research that renews the Malthusian debate.