The End of Doom (4 page)

According to a 2008 World Bank report, as a result of the increase in food supplies, per capita consumption in developing countries rose from an average of 2,100 calories per day in 1970 to almost 2,700 calories today. That report further observes that “the proportion of people suffering from hunger has fallen by half since the 1960s, from more than one in three to one in six, even as [the] world's population has doubled.” While progress has been made, some 870 million people are still undernourished.

Occasional local famines in poor countries caused by armed conflicts or political mischief do still occur. But food is more abundant today than ever before in history, due in large part to the work of Borlaug and his colleagues, and no thanks to neo-Malthusian false prophets like Paul Ehrlich and Lester Brown.

Can We Feed the World in 2050?

Looking to the future, what is likely to happen? The International Food Policy Research Institute projects that farmers will have to produce about 70 percent more food than they do today in order to provide the projected population in 2050 with a nutritionally satisfactory diet.

The journal
Philosophical Transactions of the Royal Society B
(Biological Sciences) devoted its September 27, 2010, issue to analyzing the issue of global food security through 2050. In one of the specially commissioned research articles, it is projected that world population will reach around 9 billion by 2050, and that in the second half of the twenty-first century, “population stabilization and the onset of a decline are likely.” Can the world's farmers be reasonably expected to provide enough food for 9 billion people by 2050?

Two other articles in the special Royal Society issue on global food security conclude yes. A review of the relevant scientific literature led by Keith Jaggard from Rothamsted Research looks at the effects of climate change, CO
2
increases, ozone pollution, higher average temperatures, and other factors on future crop production. Jaggard and his colleagues conclude: “So long as plant breeding efforts are not hampered and modern agricultural technology continues to be available to farmers, it should be possible to produce yield increases that are large enough to meet some of the predictions of world food needs, even without having to devote more land to arable agriculture.”

Applying modern agricultural technologies more widely would also go a long way toward boosting yields. In his 1997 article “How Much Land Can Ten Billion People Spare for Nature?,” published by the National Academy of Engineering, agronomist Paul Waggoner argued that “if during the next sixty to seventy years the world farmer reaches the average yield of today's U.S. corn grower, the 10 billion will need only half of today's cropland while they eat today's American calories.”

University of Minnesota biologist Ronald Phillips points out that India produces 31 bushels of corn per acre now, which is at the same point US yields were in the 1930s. Similarly, South Africa produces 40 bushels (US 1940s yields); Brazil 58 bushels (US 1950s yields); China 85 bushels (US 1960s yields). Today's modern biotech hybrids regularly produce more than 160 bushels of corn per acre in the Midwest. For what it's worth, the corporate agriculture giant Monsanto is aiming to double yields on soybeans and cotton by 2030. Whether or not specific countries will be able to feed themselves has less to do with their population growth than it does with whether they adopt policies that retard their economic growth.

An Overpopulated Nightmare?

Will the twenty-first century be an overpopulated nightmare, as Stephen Emmott asserts? There are good reasons to doubt it. First, let's take a look at the latest population projections by the United Nations. Every two years the United Nations Population Fund issues estimates for future population. In their latest report,
World Population Prospects: The 2012 Revision,
demographers at the United Nations boosted projected world population numbers by 600 million. The UN experts offer low-variant, middle-variant, high-variant, and constant fertility trends. The new estimates of the middle-variant projections of future population in 2050 increased from 9 billion in the UN's
2010 Revision
to 9.6 billion and from 10 billion to 10.9 billion by 2100.

The UN's middle-variant projection is generally taken to be the most likely path of future population growth. The difference between the low- and the high-variant projections is basically one child. In the new low-variant projection, world population would reach 8.3 billion by 2050, whereas the high-variant projection would result in a population of 10.9 billion by then. As the report explains, “Thus, a constant difference of only half a child above or below the medium variant would result in a global population in 2050 of around 1.3 billion more or less compared to the medium variant of 9.6 billion.”

UN estimates are not universally accepted. Many other demographers believe that the new UN projections are too high. For example, in a 2013 study, F
é
lix-Fernando Mu
ñ
oz and Julio A. Gonzalo, researchers associated with the Spanish Foundation for Science and Technology, find that past population growth has generally followed the UN's low-variant trend. Using sophisticated statistical techniques, the two calculate that future population growth will most likely continue to track the UN's low-variant trends. “Overpopulation was a spectre in the 1960s and 70s but historically the UN's low fertility variant forecasts have been fulfilled,” noted Mu
ñ
oz. If the Spanish researchers are right, world population will top out at between 8 and 9 billion by mid-century and thereafter begin declining.

In 2001, International Institute for Applied Systems Analysis (IIASA) demographer Wolfgang Lutz and his colleagues published “The End of World Population Growth” in the journal
Nature
. Lutz and his fellow researchers calculated that “there is around an 85 per cent chance that the world's population will stop growing before the end of the century. There is a 60 per cent probability that the world's population will not exceed 10 billion people before 2100, and around a 15 per cent probability that the world's population at the end of the century will be lower than it is today.” In a 2013 study in
Demographic Research,
the IIASA researchers noted that “most existing world population projections agree that we are likely to see the end of world population growth (with a peak population of between eight and ten billion) during the second half of this century.” In another 2013 study for the United Nations, the IIASA demographers project that world population will most likely peak around 2070 at 9.4 billion and fall back below 9 billion by 2100.

In a September 2013 Deutsche Bank report, demographer Sanjeev Sanyal argued that the latest UN population projections are way too high and that world population will likely peak at 8.7 billion around 2050 and then begin falling. Sanyal noted that in recent decades total fertility rates have fallen much more sharply than predicted in countries like China, India, Iran, and Bangladesh. He makes the case that rates are at the brink of similarly steep declines in current high-fertility countries such as Nigeria and Pakistan. As a consequence, Sanyal argues that “the world's overall fertility rate will fall to replacement rate by 2025. In other words, reproductively speaking, our species will no longer be expanding—a major turning point in history.” Thus, Sanyal and his colleagues predict, “World population will peak around 2055 at 8.7 billion and will then decline to 8 billion by 2100. In other words, our forecasts suggest that world population will peak at least half a century sooner than the U.N. expects.” Basically, Sanyal's analysis agrees with the researchers from the Spanish Foundation for Science and Technology that the trajectory of world population will most likely track the UN's low-variant trend and peak by the middle of this century.

In September 2014, demographers working with the United Nations Population Division published an article in
Science
arguing that world population stabilization is unlikely in this century. Instead, world population is projected to grow to around 11 billion by 2100. Nearly all of the projected increase—4 billion people—will happen in sub-Saharan Africa. However, the forecast basically assumes that Africa will remain an economic and political hellhole for the remainder of the century. In their November 2014 study,
World Population and Human Capital in the Twenty-First Century,
Wolfgang Lutz and his fellow demographers at the International Institute for Applied Systems Analysis counter that this prospect is unlikely. The chief difference between the two population forecasts is the issue of the education of women. The analysis done by Lutz and his colleagues takes into account the fact that the education levels of women are rising fast around the world, including in Africa. “In most societies, particularly during the process of demographic transition, women with more education have fewer children, both because they want fewer and because they find better ways to pursue their goals,” they note. Given current age, sex, and educational trends, they estimate that world population will most likely peak at 9.6 billion by 2070 and begin falling. If, however, the boosting of educational levels is pursued more aggressively, then world population will instead top out at 8.9 billion in 2060 and begin dropping. Let us turn now to a fuller consideration of the theories and data that underpin the latest projections of global demographic trends.

Liberate Women, Reduce Population

So why is human fertility falling even as food has become generally more plentiful? Demographers, economists, and evolutionary psychologists have all contributed to a vast and ever-growing literature on this subject. All their explanations converge on the notion that as people become wealthier and more educated, they tend to switch from having more children to having fewer healthier and more highly educated children. Demographers call this the quantity-quality trade-off.

Falling fertility rates are overdetermined—that is, there is a plethora of mutually reinforcing data and hypotheses that explain the global downward trend. These include the effects of increased economic opportunities, more education, longer lives, greater liberty, and expanding globalization and trade, among others. The crucial point is that all of these explanations reinforce one another and synergistically accelerate the trend of falling global fertility.

Even more interestingly, all of them emphasize how the opportunities afforded women by modernity produce lower fertility. Let's briefly consider some of the fascinating contemporary research on the underlying causes of the demographic transition and what will likely happen to future human population growth.

First, recent research applying insights from evolutionary biology shows that people are not reproductive automatons driven remorselessly by blind instinct to maximize the number of their offspring, as most other species are. For example, research in 2008 by University of Michigan evolutionary biologist Bobbi Low and her colleagues analyzed the reproductive patterns of women in 170 countries. Their study, “Influences on Women's Reproductive Lives: Unexpected Ecological Underpinnings,” in the journal
Cross-Cultural Research,
uses insights based on life-history theory. This approach suggests that when the risks of mortality are high, women tend to reproduce more frequently (to increase the probability of some offspring surviving to maturity) and early (to ensure reproduction before they die). In fact, Low and her colleagues found that when women can expect to live to age sixty and above, the number of children they bear falls by half. Another study in 2013 by Low and her colleagues has bolstered their finding that expecting to live beyond age sixty dramatically lowers fertility.

Looking at data from various countries confirms that fertility rates do drop as the average life expectancy of women crosses the threshold of age sixty. Consider Iran. In 1970, average life expectancy for Iranian women was fifty-four and total fertility was 6.3 children. Today, Iranian women have an average life expectancy of seventy-five and bear 1.9 children. What about Bangladesh? In 1970, female life expectancy was forty-four, and they bore 6.6 children. Today, Bangladeshi women live an average of seventy years and average 2.2 children. For India the corresponding figures for 1970 were forty-eight years and 4.9 children, and are now sixty-seven years and 2.5 children. In Brazil, female life expectancy in 1970 was sixty-one and total fertility was 4.3 children. Today, Brazilian women average seventy-eight years and total fertility stands at 1.8 children. The threshold, however, is not perfectly predictive; there are lags. Female life expectancy in Mexico was sixty-five in 1970 at a time when its total fertility rate was 5.5 children. Today, Mexican women can expect to live to about seventy-eight, and they bear 2.2 children on average. For comparison, in 1970 American women could expect to live about seventy-five years, bore 2.1 children, and infant mortality was 20 per 1,000 births. In 2012, American female life expectancy had risen to eighty-one years, births averaged 1.86 children per woman, and infant mortality had fallen to 6 per 1,000 births. By the way, the only years in which the US general fertility rate was lower than 1.86 occurred during the 1970s, when the rate fell to 1.74 births in 1976.

UN demographers expect global average life expectancy at birth to rise to seventy-six by 2050 and eighty-two by 2100. If the evolutionary biologists are right, rising life expectancy will result in falling fertility. Unfortunately, the demographers estimate that life expectancy in the world's poorest countries—many of which are severely afflicted with HIV/AIDS—is now just fifty-eight, and they project that it will reach the current global average of about seventy by 2050 and eventually rise to seventy-eight by 2100.

With regard to countries where female life expectancy is below sixty years, life-history theory frequently fails to correlate well with actual fertility rates. Some countries with low female life expectancy also have relatively low total fertility rates. For example, the increased prevalence of HIV/AIDS dramatically lowered life expectancy in a lot of African countries. According to the most recent World Bank data (2011), female life expectancy in South Africa reached sixty-two years in 1990 and has now fallen to fifty-five today. Similarly, the average Namibian woman in 1990 could expect to live to age sixty-three; that has dropped to sixty-one today. In 1990 the average life expectancy for a Zimbabwean woman was fifty-nine; it is now fifty-six. In 1990, the total fertility rates for South Africa, Namibia, and Zimbabwe were 3.7, 5.2, and 5.2, respectively. Today, despite the fact that average female life expectancy has declined, totality fertility rates in those countries have fallen to 2.4, 3.2, and 3.6 children, respectively.