Population & Resources

British economist Thomas Malthus (1766–1834) was one of the first to argue that the world’s rate of population increase was far outrunning the development of food supplies. In An Essay on the Principle of Population, published in 1798, Malthus claimed that the population was growing much more rapidly than Earth’s food supply because population increased geometrically, whereas food supply increased arithmetically. According to Malthus, these growth rates would produce the following relationships between people and food in the future:

Malthus’s Theory

Malthus made these conclusions several decades after the United Kingdom had become the first country to enter stage 2 of the demographic transition, in association with the Industrial Revolution. He concluded that population growth would press against available resources in every country unless “moral restraint” produced lower CBRs or unless disease, famine, war, or other disasters produced higher CDRs.

Neo-Malthusians

Malthus’s views remain influential today. Contemporary geographers and other analysts are taking another look at Malthus’s views because of Earth’s unprecedented rate of natural increase during the late twentieth century. Neo-Malthusians argue that characteristics of recent population growth make Malthus’s thesis more frightening than when it was first proposed more than 200 years ago.

In Malthus’s time, only a few relatively wealthy countries had entered stage 2 of the demographic transition. Now, relatively poor countries are in stage 2. As a result, the gap between population growth and resources is wider in some countries than even Malthus anticipated.

World population growth is outstripping a wide variety of resources, not just food production, according to Neo-Malthusians. They argue that the world faces a frightening future in which billions of people are in desperate competition for food, water, and energy.

Neo-Malthusians & Critics

Evidence from the past half-century lends support to both Neo-Malthusians and their critics. Worldwide, carrying capacity in terms of food production has increased during the past half-century somewhat more rapidly than Malthus predicted. In India, for example, rice production has followed Malthus’s expectations fairly closely, but wheat production has increased twice as fast as Malthus expected. Better growing techniques, higher-yielding seeds, and cultivation of more land have contributed to the increase in the food supply (see Chapter 9).

On the population side of the equation, recent evidence indicates that Malthus has been less accurate. His model expected population to quadruple during a half-century, but even in India—a country known for relatively rapid growth—population has increased more slowly than that, and it has also increased more slowly than the country’s food supply.

On the other hand, population growth may be exceeding carrying capacity in Africa. Rapid population growth has led to the inability of the land to sustain life in parts of the region. As the land declines in quality, more effort is needed to yield the same amount of crops. This extends the working day of women, who have the primary responsibility for growing food for their families. Women then regard having another child as a means of securing additional help in growing food.

Pause & Reflect 2.4.4

Calculate the units of population and food that Malthus predicted would exist in 200 years.

Sustainability & Our Environment

Earth’s Resources & Our Growing Population

Evidence from China (the world’s most populous country) and Africa (the world’s fastest-growing continent) concerning the relationship between population growth and food production lends support to both Neo-Malthusians and their critics.

1. The red line below shows population change. Which population line more closely resembles Malthus’s theory of population growth? What might account for this difference?

2. The brown line is the food production index. The index is calculated to be 100 in 2005. An index higher than 100 indicates more food production than in 2005, and an index below 100 indicates less food production than in 2005. How do the food production lines for the two areas compare with Malthus’s theory? What might account for the difference?

Figure 2-60 Food Production and Population: China

Figure 2-61 Food Production and Population: Africa