Summary

Growth Slowing but Continuing, Inducing Scarcity “Tipping Points”

As quickly as human beings communicate and travel from continent to continent, we are still fundamentally earthbound. Even the word “globalization” reminds us that we inhabit a globe, a watery sphere in the vastness of the universe that supports life, including human life.

In the year 2015 (the year in which the Millennium Development Goals are to supposed to be achieved), despite worries in some countries that there are too few births, about 7.2 billion human beings are projected to live on this globe, a 10 percent increase from the present. The health of the planet and its natural resources reflects the impact of humanity more acutely each year. New data on human population and the state of critical natural resources, compiled and calculated by PAI, demonstrate two key trends:

• Human pressure on renewable freshwater, cropland, forests, fisheries, and the atmosphere is unprecedented and continually increasing.
• Recent declines in human fertility already have slowed the pace of this increase, providing hope that human pressure on the environment eventually will peak and then subside.

This second trend offers a rare glimmer of hope that human civilization may one day become truly sustainable. It is not sustainable today, as the new data make clear. Despite a growing global economy and generally adequate energy and food supplies, the renewable natural resources most important to human life show dramatic signs of loss, scarcity or ill health as growing human populations compete for the finite supplies of each resource. Human activities are warming the global climate, yet emissions of heat-trapping gases from those activities show no signs of subsiding any time soon.

Nonetheless, because population growth is slowing, the future of the relationship between people and the renewable natural resources on which they depend has begun to appear more hopeful than it once did. Both population growth rates and density, however, are more varied than ever before. So, too, are the ratios of availability of critical natural resources to people in different countries. In some regions—notably in sub-Saharan Africa and parts of Asia—large families and early pregnancies provide strong momentum for population growth that could continue for generations to come. Nonetheless, the braking of this growth has been significant enough that many analysts of natural resources are more optimistic about the future of resource availability than they were in the early 1990s. Some demographers and other analysts, by contrast, worry that the slowing and eventual peaking of population growth will make for new crises related to the aging of populations. While these aging trends may challenge pension and social security programs as well as other aspects of governance and economic policy, the prospect for environmental sustainability is bright. It is hard to imagine any development more positive for the entire range of environmental problems humanity faces than a peak in population.

This update to the original People in the Balance analyzes new data on population growth and the state of critical natural resources. Among its key findings:

• In 2005, 448 million people will live in countries with less than 0.07 hectare of cultivated land per person. This benchmark is considered the bare minimum capable of supplying a vegetarian diet for one person, under ideal conditions, and without use of artificial chemical inputs and without unsustainable loss of soil or soil nutrients. The number of people living in such critically land-scarce countries—they now include Egypt, Bangladesh and Jordan—is projected to increase to between 559 million and 706 million in 2025, depending on rates of population growth. [See chart : World Population Trends and Projections] Moreover, by 2025 a population nearly as large as today’s global total of 6.5 billion could live, under the highest UN population projection, in countries that have less than 0.21 hectare of cultivated land per person, a point below which most countries must struggle to remain agriculturally self-sufficient. These calculations assume no major changes in the extent of cropland in each country, as most of the food produced in the future is expected to come from today’s farmland. Cropland availability is an especially interesting indicator. A PAI study, The Security Demographic: Population and Civil Conflict After the Cold War, published in 2003, found significant correlations between cropland-scarce countries and civil conflicts between 1970 and 2000. These correlations add to fears about the future of security in an interconnected world. In at least one hopeful change, the projected increases in land-scarce population is lower than in PAI’s last update on population and natural resources, due in large part to lower projected population growth in key land-scarce countries.
• By the year 2025, between 2.75 billion and 3.25 billion people could be living in either water-scarce or water-stressed conditions (that is, with less than approximately 1,700 cubic meters of renewable fresh water per person per year), depending on future rates of population growth. This compares to 745 million people who live in these circumstances in 2005. Water shortage is likely to grow especially acute in the Middle East—by 2025 both Jordan and the Occupied Palestinian Territories are projected to have less than 150 cubic meters of renewable fresh water per person per year—and in much of Africa.
• Global fish production rose slightly in 2002 (the last year for which UN data is available) from the total recorded in 2001. The UN production figures have increased in most years since the mid-1980s, based mostly on the expansion of aquaculture in China. Most capture fisheries worldwide—those based on catching rather than raising fish—remain fully exploited or in decline, meaning that without the farming of fish, global production would be generally declining. While the population of fishers is has been increasing in recent years, the amount of fish caught per fisher is declining. Moreover, some researchers challenge the UN production figures over the last two decades and believe that global fish production has actually been declining throughout that time.
• In 2005 more than 2.21 billion people lived in 46 countries—such as Haiti, Ethiopia and El Salvador—with less than 0.1 hectare of forested land per capita, an indicator of critically low levels of forest cover. Based on current trends in deforestation, by 2025 the number of people affected could rise to as many as 3.38 billion under the highest population projection.
• More than one-fifth of the world’s population lives on the 12 percent of its land surface with the highest densities of non-human species. Human population is growing much faster in these biodiversity hotspots than in the world or even in developing countries as a whole. And it is growing faster still in the three thinly-settled tropical wilderness areas —the Amazon basin in South America, the Congo forest in central Africa, and forests of New Guinea—that are the last refuges for much of the world’s remaining terrestrial species.
• In 2002, per capita emissions of carbon dioxide—at 1.12 metric tons for the average person on earth— were the highest they had been since 1998. Intriguingly, although the terrorist attacks on the United States on September 11, 2001 shocked the global economy, they made no noticeable impact on the world’s use of fossil fuels, which grew a shade faster than population in 2002. Global emissions in 2002 were just shy of 7 billion metric tons of carbon, twice what they were just 35 years ago. Industrialized nations with relatively slower population growth contribute the lion’s share of these emissions—especially the United States, with less than 5 percent of world population and 23 percent of global CO2 emissions. The average American sends hundreds of times more CO2 and other greenhouse gases into the atmosphere each year than does the average person in Rwanda, Laos or Mali. Per capita emissions in many developing countries, however, are now rising as industrialization and the use of motorized transportation expand.

Population is hardly the only force applying pressure to the environment and natural resources. But the environmental challenges humanity faces in the 21st century and beyond will become harder to address as the number of people continues to increase. For each of the natural resources considered here, the long ascent of population reveals itself as a critical variable influencing resource availability on local, regional and global scales.

Despite a certain bleakness in the historical relationship, there is little-known good news for environmentalists, policymakers and the general public. Increasingly, young people on every continent want to delay pregnancy and childbearing and ultimately to have fewer children per couple than at any time in human history. Likewise, in greater proportions than ever, women and girls in particular want to go to school and to college, and they want to find fulfilling and well-paid employment.

Helping people in every country obtain the information and services they need to put these productive and reproductive ambitions into effect is all that can be done, and all that needs to be done, to bring world population growth to a peak in the new century. What is needed is for government and the private sector to make reproductive health services available to all who seek them, to make sure that girls and boys can go to and stay in school, and to make economic opportunities as accessible to women as to men. Combined with developing new energy- and material-efficient technologies and moving toward saner definitions of what it really means to “live richly,” these strategies can bring humanity into enduring balance with the environment and the natural resources that people will always need.