Debating Population

World population stood at 1 billion in 1804, increased to 3 billion by 1959, 4 billion in 1974, 5 billion in 1987 and just 12 years later in 1999 it amounted to 6 billion. In October 2011, the world reached a population figure of 7 billion people, fuelling another debate about the implications of this figure and its projected growth to a possible 10 billion by the end of this century.

The highest population growth rates are occurring in the Developing World with Africa’s population projected to triple this century (it has 39 of the world’s high fertility countries); Asia will remain the most populous part of the globe with its population expected to reach a peak about 2050 and then decline (Asia has 9 high fertility countries); Latin America (with 4 high fertility countries) expect to reach a peak some 25 years earlier.

Today, the world’s 5 most populous countries are China, India, the United States, Indonesia and Brazil with 58% of world population living in the 10 most populous countries.

Much has changed in relation to population over the past half century – for example, average life expectancy increased from about 48 years in the early 1950s to 68 in the first decade of this century. Infant deaths dropped dramatically from some 133 in every 1,000 live births in the 1950s, to 46 in the period 2005 to 2010 and immunisation programmes reduced the prevalence of childhood diseases worldwide. In addition, fertility (the number of children a woman is expected to have in her childbearing years) dropped by more than half, from about 6.0 to 2.5, partly because of economic growth and development but also because of other equally important developments in social and cultural practices and because of greater access for women to education, income-earning opportunities and to sexual and reproductive health care, including modern family planning.

World Population (and wealth) by Region 2000 and projected for 2050 (%)

Africa13.25 (1%)23.55
Asia60.74 (24%)55.26
Europe11.87 (32%)7.73
Latin America & Caribbean8.52 (6%)8.07
North America5.12 (34%)4.80
Oceania5.12 (34%)4.80

Sources: UN, Dept. of Economic and Social Affairs, Population Division (2011); World Population Prospects: The 2010 Revision; UNFPA (2011) State of the World Population World Institute for Development Economics (2006); The World Distribution of Household Wealth, United Nations University

With the vast majority of population growth occurring in the Developing World, it was inevitable that the debate would focus on population and its implications for the planet. Today the debate centres around a number of issues – whether population growth per se threatens the planet and is therefore unsustainable or whether the conspicuous overconsumption of the Developed World is the real threat; how best to realise stability in population growth while protecting and promoting women’s and children’s rights and the issue of food (in)security (‘can we feed a world population of 10 million plus?). These debates are briefly introduced below.

Population Growth & Sustainability

In 1993, a meeting of scientists from some 60 academies of science worldwide argued that the world was experiencing an ‘unprecedented’ explosion in population and that this explosion was linked to many environmental and social problems such as carbon dioxide emissions, pollution and global warming. In 2009, the UK’s Chief Scientific Advisor, Professor John Beddington predicted a ‘perfect storm’ by 2030, generated by growing population numbers, decreasing energy reserves (especially oil) and extensive food shortages. He warned:

‘If we don’t address this, we can expect major destabilisation, an increase in rioting and potentially significant problems with international migration, as people move out to avoid food and water shortages.’

Ian Semple, Guardian Newspaper, March 18th, 2009

Economic growth and rising incomes in countries such as China and India have also increased demand worldwide for resources and energy in addition to consumer goods placing yet further demands on the planet and its people. For the Washington-based Worldwatch Institute (2010) the growth of population is directly linked to climate change; human-caused climate change is fundamentally an imbalance of scale ‘…as people release heat-trapping gases into Earth’s atmosphere faster than the oceans and living things can remove them’. This imbalance has arisen from the explosion of technologies as a result of the combustion of fossil fuels over the past 3 centuries and the greater than sevenfold increase in human numbers since that time.

In contrast, Indian scientist and activist Vandana Shiva argues that non-sustainable population growth is a symptom and a product of non-sustainable development and not vice-versa. Population growth does not exist in a vacuum but in a world of gross and growing inequality where the rich minority consume far more than a reasonable share of the earth resources and produce the majority of its pollutants and waste thus fuelling climate change. Western style ‘development’ not population growth is where the focus of debate should be. For commentators such as Shiva, it is the energy intensive industrialised agricultural systems of the West that ‘divert food and land from the poor to the non-sustainable energy needs of the rich’ that are unsustainable not the growth in population numbers per se.

For commentators such as William Rees of the University of British Columbia, it is the ‘resource-hogging’ countries such as Canada, the United States and Australia that place huge demands on the Earth, not the poor. These countries have enormous ecological footprints – ‘each of us in North America needs 20 to 25 acres of land to produce our food and assimilate all our wastes; it’s a fairly substantial chunk of territory… everything we do, whether it’s burn gasoline in oversize personal transportation units, over-wrap products in nuclear-bomb-proof plastic, grow food, smelt metal, saw wood, pump freshwater, make junk mail, or pave highways, should show up in our ecological footprint…’

For Rees, the matter is, in one sense, straightforward – if everyone was to live North America, we would need four or five planet Earths. Focus on reducing population numbers alone, without focusing on resource use and waste production or suggesting that reducing the numbers of the world’s poor while ignoring the behaviour of the rich is not a sustainable proposition.

Laruie Mazur of the Population Justice Project agrees. She says that the issue of population size does matter, but so too does our consumption:

“… demographic projections say we’ll get to anywhere from 8 billion to 11 billion by 2050. Let’s use 9 billion, the UN’s medium projection — though it’s far from a sure bet. Now let’s look at per capita CO2, an imperfect but still useful proxy for other greenhouse gas emissions, and for environmental impact generally. As you know, Americans emit more CO2 per capita than anyone on earth–about 20 tons per person, per year. Europeans emit about half that, and most sub-Saharan Africans come in at a ton or less. Let’s say the US was able to cut its emissions by three quarters, and Europeans cut theirs in half. While we’re at it, let’s have a massive redistribution of wealth and technology, which enables everyone on earth to converge at an emissions level of 5 tons per person, per year — about the level of Mexico today. Even in this fantastically rosy scenario, with a population of 9 billion and per capita emissions of 5 tons per person, global carbon dioxide emissions would rise to 45 billion tons of CO2 per year — a 50% increase over our current, ruinous level. In our equitable world scenario, the difference between a world population of 8 billion and one of 11 billion would be about 15 billion tons of CO2 per year — half our current emissions and quite possibly the margin between a manageable climate crisis and catastrophe.

In an equitable world, population matters. In fact, the only scenario in which population doesn’t matter (much) is one where the current inequitable divide between rich and poor remains fixed for all time.”

Laurie Mazur, Population Justice Project (

Climate scientist Brian O’Neill who has studied correlations between population size and greenhouse gas emissions agrees: “slowing population growth could make a contribution to solving the climate-change problem …” However, he continues by saying that “while population size is a driver of greenhouse gas emissions, it is not necessarily the most important driver. Increases in GDP also were found to have a roughly proportional effect on emissions, and technology effects were equally important…. slower population growth alone is no guarantee of lower emissions; other factors, notably energy use, can easily outweigh the positive impact of slower growth… In general, lower population growth is associated with — but cannot guarantee — lower emissions.”

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Population Growth & Women’s Rights

Much of the debate around population and sustainability focuses on women’s reproductive rights and in particular women in the developing world having fewer children. With concerns around the expanding world population and the related pressure on the environment as a result, the response is focussed on family planning. But, as Laurie Mazur points out, “it’s not just about family planning [or] by coercing poor women to have fewer children” which in itself has contributed to the violation of the rights of women throughout the world, it is about “universal access to family planning and other reproductive health services, educating girls and empowering women, and promoting sustainable, equitable development–are all vitally important ends in and of themselves.” She instead argues for ‘Population Justice,’ which considers the realities of the poor. Being socially and economically deprived, often constrained by their gender, ensures that there are limited options available to marginalized women and girls – and indeed families, in making informed, affordable and accessible reproductive healthcare choices…

Some of the key issues in the reproductive rights debate and some suggestions on what can be done include:

  • Economic Systems and Population Growth – Mazur claims that “rapid population growth is a by-product of the inequity produced by our current economic system. High fertility correlates perfectly with poverty; the poorest families in the poorest countries have the highest fertility rates.”
  • Gender inequality. Throughout the world, girls and women have no alternative to early marriage and frequent childbearing (see case study 4) – “What does reproductive choice mean to an 11 year-old girl who is married against her will, whose sexual initiation is indistinguishable from rape, and who begins childbearing before her pelvis is fully formed, at great risk to her life and health?” (Laurie Mazur). By eradicating gender bias from law, economic opportunity, health, and culture women will own, inherit, and manage property; divorce; obtain credit; and participate in civic and political affairs on equal terms with men are more likely to postpone childbearing and to have fewer children compared to women who are deprived of these rights.
  • Girls’ education. In every culture surveyed to date, women who have completed at least some secondary schooling have fewer children on average, and have children later in life, than women who have less education. It empowers women and increases their economic value outside of the home.
  • Universal access to reproductive health for both men and women: Some 70% of maternal deaths worldwide and nearly half of newborn deaths could be averted if there was universal access to health and reproductive services. With two in five pregnancies reported as mistimed or never wanted, enabling girls and women to plan and space childbearing, reproductive health services can improve women’s health, educational status and economic well-being.
  • Providing age-appropriate reproductive health education for young people that informs them about issues related to puberty, intercourse, sexual health, options for birth control, and respecting the sexual rights and decisions of individuals can help prevent unwanted pregnancies, promote gender tolerance, and impact on birth rates.
  • By integrating advocacy and/or propaganda free lessons on population, environment, and development into school curricula at multiple levels in schools could educate students to make well-informed choices about the impacts of their behaviour, including childbearing and on the environment.
  • Refraining from, promotion of fertility in the ‘First World’. Countries in Europe and the US have discussed and/or implemented a reward system in an attempt to increase fertility within these countries to deal with the effects of an ageing population in those countries.
  • The population debate looks at ending policies that reward women and families based on the number of children that they have. An alternative suggestion looks at tax and other financial benefits aimed at helping parents by linking these not to the number of children they have, but to parenthood status itself.
  • Quantify the environmental costs and impacts of having additional children – calculating the additional taxes and increased food costs associated with having more children, which may encourage couples to reconsider their reproductive choices.
  • Adjust to the reality of an ageing population through societal adjustments, rather than boosting childbearing through government incentives and programmes.

It is argued that if most or all of the above strategies were put into effect, global population would peak and subsequently begin a gradual decline before 2050, ensuring sustainable development of natural resources and global stability into the future.