PUBLISHED ONLINE MONDAY 21 SEPTEMBER 2009
How do we best approach the problem of unsustainable population growth? How do we cope with
unprecedented rates of demographic change? What is the relationship between population size and
conflict? And should we change retirement age as population age rises?
These are just some of the questions addressed in the latest issue of the journal Philosophical
Transactions of the Royal Society B* which is all about population growth.
*Please note and reference the full title if possible in print.
Please note that this paper is not available on our press site; full papers available on request. Please
also note that the research papers published in Royal Society journals are written by independent
authors and do not necessarily represent the views of the Royal Society.
The Impact of Population Growth on Tomorrow's World. A theme issue compiled
by Roger Short and Malcolm Potts
Media abstracts from the articles:
Introduction: Population Growth in Retrospect and Prospect (doi:10.1098/rstb.2009.0144)
The world’s population, currently 6.8 billion, is expected to reach 9.1 billion by 2050, and is growing
by 78 million a year. Ninety-five percent of this growth is occurring in developing countries, and it is
unsustainable. If we could grant the women of the developing world freedom from the tyranny of
unwanted fertility by giving them access to contraception and safe abortion, every birth could
become a wanted birth, and the birth rate would come tumbling down. Since Global Warming is
due to human environmental pollution, the fewer of us there are in the world, the better.
Contact: Dr. Roger Short, University of Melbourne, r.short@unimelb.edu.au,
THE WORLD IN 2050: A Scientific Investigation of the Impact of Global Population Growth on a
Divided Planet Summary Statement (doi:10.1098/rstb.2009.0180)
At the Bixby Forum economists, climate experts, demographers, family planning specialists and
others discussed the impact of the projected growth in global population from 6.8 million today to
between 8 and 10.5 billion in 2050. They emphasized that current high rates of population have
serious adverse effects on the health of women and children, the stability and progress of society,
and the natural environment. At the same time, 80 million unintended pregnancies occur annually
and there is a large unmet need for family planning. Making every birth a wanted birth is vital to
creating a healthier, more equitable, and stable world.
Contact: Dr. Malcolm Potts, University of California, Berkeley, potts@berkeley.edu, 510 642 6915
Population priorities: the challenge of continued rapid population growth
(doi:10.1098/rstb.2009.0183)
Today’s least developed nations are growing up to four times as fast as nineteenth century Europe.
Rapid population growth at this level will have a severely adverse impact on their economic
prospects. Though not sufficient, capital accumulation for growth is absolutely essential to
economic growth and a falling birth rate. While there are good reasons for objecting to the enforced
nature of the Chinese one child policy, we should not underestimate the positive impact which that
policy has almost certainly had and will have over the next several decades on Chinese economic
performance.
Contact: Dr. Adair Turner, Financial Services Agency.
Human population growth and the demographic transition (doi:10.1098/rstb.2009.0137)
The world and most regions and countries are experiencing unprecedentedly rapid demographic
change. The most obvious example of this change is the huge expansion of human numbers: 4
billion have been added since 1950. Projections for the next half century expect a highly divergent
world, with stagnation or potential decline in parts of the developed world and continued rapid
growth in the least developed regions. Other demographic processes are also undergoing
extraordinary change: women’s fertility has dropped rapidly and life expectancy has risen to new
highs.
Contact: Dr. John Bongaarts, Population Council, jbongaarts@popcouncil.org, 212 3390660
Stall in Fertility Decline in Eastern African Countries: Regional analysis of patterns,
determinants and implications (doi:10.1098/rstb.2009.0166)
In 1988 demographers projected the population of Kenya in 2050 would reach about 50 million.
However, in the second half of the 1990s, the focus on family planning was removed, budgets
collapsed and fertility declines slowed, stalled, or were reversed. The poorest women and
adolescents were often most affected. As a result of stalled fertility, the population of Kenya in 2050
is now projected to be over 80 million. The scale of these changes varies between countries and
across social groups, but persistent high fertility is undermining development across sub-Saharan
Africa and attention must be refocused on to family planning.
Contact: Dr. Alex Ezeh, APHRC, aezeh@aphrc.org, +254-20-272-0400
Declining populations (doi:10.1098/rstb.2009.0185)
Half the world’s population has two children or fewer. As family size falls, the average age of the
population rises. Currently, British men spend 30% of their adult working life as retirees. Lord Adair
Turner, who chaired the UK Pensions Commission in 2002, emphasizes that policies aimed trying to
raise fertility or increase immigration merely pass the problem to the next generation. Instead, he
argues that, as people enjoy more years of healthy life, a slow, a modest rise in the age of
retirement (e.g. to 68.5 in 2050) will remove most of the financial burden on the work force.
Contact: Dr. Adair Turner, Financial Services Agency.
Population, Poverty and Economic Development (doi:10.1098/rstb.2009.0145)
The article summarizes recent research on the relationship between population growth and
economic development and concludes that nearly all recent evidence strongly suggests that high
fertility and rapid population growth inhibit economic development of societies and tend to entrap
individuals and families in poverty.
Contact: Dr. Steven Sinding, Guttmacher Institute, ssinding@gmail.com, +1 212 248-1111
Sola schola et sanitate: Human capital as the root cause and priority for international
development? (doi:10.1098/rstb.2009.0156)
This paper summarizes new evidence supporting the hypothesis that among the many factors
contributing to international development, the combination of education and health stands out as a
root cause on which other dimensions depend. This is based on new reconstructions and projections
of populations using the demographic method of multi-state population dynamics and a series of
systems analytical population-development-environment (PDE) case studies that assess the role of
population and education relative to other factors in the struggle for sustainable development. Only
by adding the “quality” dimension of education to the narrow focus on size and age structure can
some of the long-standing population controversies be resolved.
Contact: Dr. Wolfgang Lutz, IIASA, lutz@iiasa.ac.at, +432236807294
Population Policies, Programs and the Environment (doi:10.1098/rstb.2009.0162)
Human consumption, primarily to meet increasing demands for food, fresh water, timber, fiber, and
fuel, is depleting the Earth’s natural resources and impairing ecosystem capacity. The increase in
world population from 2.6 billion in 1950 to 6.8 billion in 2009 has been a major contributor to
environmental damage. Strengthening family planning services is crucial to slowing population
growth, now 78 million annually. More than 200 million women in developing countries prefer to
delay their next pregnancies or stop bearing children but they lack access or face other barriers to
using contraception. An estimated $15 billion per year is needed for family planning.
Contact: Ms. Sarah Gilbert, University of California, San Francisco (UCSF),
gilberts@obgyn.ucsf.edu, +1 415-502-3928
Traversing the Mountaintop: World Fossil Fuel Production to 2050 (doi:10.1098/rstb.2009.0170)
Fossil fuels – petroleum liquids, natural gas, and coal – have been the dominant source of world
energy for a century, and their combined growth has exceeded population increase. During the
past 50 years fossil fuel production was limited by energy demand: between now and 2050 it will be
limited by the amount and characteristics of remaining the resources. World fossil fuel production
per capita will begin an irreversible decline between 2020 and 2030. Ultimately, it will be the
capacity of the atmosphere to absorb CO2 rather than the quantity of fossil fuels in the ground that
limits production.
Contact: Dr. Richard Nehring, Nehring Associates, rnehring@nehringdatabase.com,
Considering population and war: a critical and neglected aspect of conflict studies
(doi:10.1098/rstb.2009.0151)
Population growth and population decline are slow and often overlooked, but they have a
significant impact on the risk of conflict. Rapid population growth leads to a ‘youth bulge.’ A surplus
of young males increases the risk of conflict. Youth bulges in Somalia or Afghanistan feed al Qaeda
recruiters. The Moslem population of Europe has gone from insignificant to 15 to 18 million in a
generation: will this new minority become integrated or radicalized? Will an imbalance in the sex
ratio in China prove destabilizing? Is the fact Iran has fewer young males than its neighbors a reason
for developing nuclear weapons?
Contact: Prof. Bradley Thayer, Baylor University, Bradley_Thayer@baylor.edu,
Making family planning accessible in resource-poor settings (doi:10.1098/rstb.2009.0172)
The poorest couples have the highest fertility, the lowest contraceptive use, and the highest unmet
need for contraception. It is imperative to make family planning more accessible in low resource
settings. Four critical steps should be taken to increase access to family planning in resource poor
settings: a) increase knowledge about the safety of family planning methods; b) ensure
contraception is genuinely affordable to the poorest families; c) ensure supply of contraceptives by
making family planning a permanent line item in health care system’s budgets; and d) take
immediate action to remove barriers hindering access to family planning methods.
Contact: Dr. Ndola Prata, University of California, Berkeley, ndola@berkeley.edu, 510 643 4284
The theoretical and political framing of the population factor in development
(doi:10.1098/rstb.2009.0174)
There is reluctance to talk about the population factor in development as long as consensus is
absent on what causes birth rates to decline. The belief that family size will fall only after people are
better educated or wealthier is not supported by the evidence. Instead, the many barriers between
women and the technologies and information required to manage their childbearing needs to be
understood. When these barriers are removed then family size falls, even in illiterate, poor societies.
Voluntary family planning in the world’s least developed regions is a prerequisite to improving
education and lifting people out of poverty.
Contact: Prof. Martha Campbell, University of California, Berkeley, campbell@berkeley.edu, 510524-4320
Where next? (doi:10.1098/rstb.2009.0181)
Population growth interacts with many other factors, from global warming to security. Rapid
population growth and unprecedented economic activity threatens the future of the planet.
Slowing population growth is essential if the world’s poor are to be lifted out of poverty.
Fortunately, the assumption that people must become richer or better educated before they have
fewer children is being replaced by a clearer understanding of the many barriers that separate
women from the knowledge and technologies they need to limit childbearing. When these barriers
are removed family size falls even in poor, illiterate communities. Much greater attention must be
given to population, voluntary family planning and education.
Contact: Dr. Malcolm Potts, University of California, Berkeley, potts@berkeley.edu, 510 642 6915
NOTES FOR EDITORS
1. The Royal Society is an independent academy promoting the natural and applied sciences.
Founded in 1660, the Society has three roles, as the UK academy of science, as a learned
Society, and as a funding agency. It responds to individual demand with selection by merit, not
by field. As we prepare for our 350th anniversary in 2010, we are working to achieve five
strategic priorities, to:





Invest in future scientific leaders and in innovation
Influence policymaking with the best scientific advice
Invigorate science and mathematics education
Increase access to the best science internationally
Inspire an interest in the joy, wonder and excitement of scientific discovery
2. The Royal Society is one of the most Open-Access friendly of all science publishers. Our
approach is to widen access to research outputs in a number of ways, all of which are
compatible with the long term sustainability of the publishing process. We are partners in a
number of international schemes operated by the UN and WHO to make scientific journal
articles available immediately and free of charge to the world’s poorest nations.