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Reaching 10 billion: opportunity or concern?

Understanding the facts about population change

Published: 8 July 2016

A ballooning world population, projected to hit 10 billion around the middle of this century, is raising public concerns, according to Southampton research.

The study into public perceptions of population growth shows people's concerns focus on food and water shortages, species extinctions and other catastrophic consequences. But is there any evidence to suggest these fears are valid?

Research highlights talks to Dr Ian Dawson of the Southampton Business School’s Centre for Risk Research, and Professor Jane Falkingham, Dean of Social, Human and Mathematical Sciences, about the facts surrounding population change.

Dr Ian Dawson, Southampton Business School’s Centre for Risk Research

When the global human population reached seven billion in 2011, it attracted a lot of media attention and generated a wealth of related discourse including discussions about the adverse effects of global population increase. Our new research attempts to assess the extent to which the public shares these concerns.

Supported by the University’s Annual Adventures in Research fund, we conducted a telephone survey in the UK designed to: collect information about public perceptions and knowledge of global population growth, the willingness of individuals to adopt mitigation or precautionary behaviours, and the underlying reasons for variations in these factors.

Individuals who perceived greater levels of risk from population growth were generally those who indicated a greater willingness to embrace mitigation behaviours and support preventative actions. This is particularly important as it suggests that greater concern about the potential adverse effects of global population growth might act as an important catalyst for behavioural changes that could help humanity better manage some of the related challenges, such as conserving valuable resources and mitigating human induced climate change.

Public discussions about global population growth are often absent from modern political discourse. In democratically representative politics, this is at odds with the finding that public concern about global population growth is relatively high.

Dr Ian Dawson - Southampton Business School’s Centre for Risk Research

Ecological damage and resource shortages

Respondents who perceived medium-to-high risks were concerned about ecological damage, resource shortages and violent conflict. Approximately half of those who took part in the survey believed that governments had the greatest ability to influence global population levels, and most agreed national governments were not doing enough to tackle the issue. Older respondents with relatively low risk perceptions were the least willing to change their behaviour.

While we found that many younger people perceived the risk of global population growth as relatively high, it could be seen as reassuring that we found that these younger people, who stand to inherit and occupy a more populated world, are those that tended to be most willing to adopt mitigation actions.

Public discussions about global population growth are often absent from modern political discourse. In democratically representative politics, this is at odds with the finding that public concern about global population growth is relatively high. Hence, it could be argued that there is a need for policymakers to take greater steps towards openly discussing global population growth and to make greater efforts to gauge and respond to the public’s related concerns.

Such open discussions could play an important part in helping people to develop a better understanding of global population growth and its potential effects – to work collectively towards proportionate responses that enable humanity to capitalise on any associated benefits while carefully managing any related risks.

Professor Jane Falkingham, Dean of Social, Human and Mathematical Sciences and Director of Economic and Social Research Council (ESRC) Centre for Population Change

We live in exciting times to study demography. For most of human history, the world’s population was less that several hundred million and up to the 17th century, population growth was slow and unstable. In some years, the population even decreased as epidemics, famines and conflicts took their toll. It is estimated that the plague, or Black Death, resulted in the population of Europe falling by as much as a third in the two years between 1347 and 1349. The world reached the landmark of being home to a billion citizens in around 1800 and then took the next 130 years to reach two billion in 1930. Since then population growth has really taken off with the third billion taking another 30 years. Four billion was reached in 1974 and it then took just 13 years to reach five billion in 1987 and a further 11 years to reach six billion in 1998. The rate of global population growth has since started to slow down; we reached seven billion in 2011 and are predicted to hit the eight billion landmark in 2025.

The drivers of population change

Why has this happened? Population change at a local level depends on trends in its three components: fertility, mortality and migration. At a global level it is the difference between the number of births and deaths (ie natural increase) that drives population change as we have not yet found a way to migrate to new planets. The unprecedented rise in global population therefore can be seen as one of human’s greatest achievements, being driven by falls in mortality as a result of improvements in public health, sanitation, nutrition and medical advances. As more children survive to adulthood, and with economic and social development altering the economic costs and benefits of children, societies and individuals around the world have adapted their behaviour to have less children. Fertility rates have fallen in most countries in the world, including most notably in China and India.

Most demographers around the world believe that the world’s population will probably stabilise between 10 and 11 billion by the end of the century, marking the end of three centuries of unprecedented change, the likes of which we will never witness again. Whether it does so, and at what speed it gets there, is primarily dependent on how fast fertility falls in sub-Saharan Africa and parts of the Middle East. Although the total fertility rate (TFR) (ie the number of children on average a women bears over her reproductive life span) has fallen dramatically in the last half century, not least in China, there remain some countries in Africa where the TFR is still over five.

Population and resources

Concerns over the relationship between population and resources date as far back as to the writing of Thomas Malthus in the late 18th century. However, the connection between growing population and diminishing resources is not straightforward. Concentrating solely on population growth risks is missing the point. Seven out of 10 countries with the highest population growth rates today are in sub-Saharan Africa, reflecting their high birth rates. However even though the populations in these countries are growing faster than those in developed countries, they are currently using fewer of the world’s resources on a per capita basis; with the majority of world resources being consumed in Western Europe and North America.

What will be critical going forward for the management of global resources is how we manage the process of economic and social development and the use of resources in a balanced fashion. As countries such as China and India become more economically developed, people are starting to change their diets, live more technologically driven lives and travel. While this puts further pressures on resources, these countries are perfectly entitled to enjoy the same standards of living and quality of life as we do in Europe and North America.

Ecological damage is definitely an issue we should be concerned about. Slowing population growth through better education, especially of girls, and through the provision of appropriate family planning methods and improving reproductive health, remains a priority for demographers and policymakers alike. However, reducing the pace of population growth alone is not the solution; it is also critically about how resources are used and distributed. Current research shows that of our 7.5 billion global citizens, about a billion overeat, a billion are hungry, and another billion are malnourished.

It is all about human behaviours, less about the size of the population, and more about how we live together.

Professor Jane Falkingham - Director of Economic and Social Research Council (ESRC) Centre for Population Change

The UN suggests about half of all food produced for human consumption goes to waste. In developed countries 50 per cent of all food is discarded after purchase, while in developing countries, 50 per cent is wasted prior to purchase due to pest infestation, poor storage and poor access to markets. Thus, we already grow enough food to nourish at least 10 billion people; today the uneven distribution and use of resources across the globe may be a more potent cause of malnutrition and hardship than any potential ceiling to what the planet can supply.

Ian’s research also highlights the lack of public knowledge around demographic issues in the UK. At the ESRC Centre for Population Change, we aim to improve the understanding of the key drivers and implications of population change and are actively seeking to engage the public in our research to address this issue. Last year we had an exhibition that toured the UK, talking to people about what population change means to them, their communities and their lives and how their childhood, family life, lifestyle and work all affect how long we live. The exhibition is going to be in Brussels at the European Parliament in September.

Having a population of 10bn is a challenge, but it is a challenge that we all will have to rise to. There is very little we can do to prevent this occurring as 7.5 billion of those people are already here, and many of these are the future parents of the future children. We can slow population growth down by providing better access to family planning so that all those who want it can get it, and by improving education across the world so that poverty is reduced. But, critically we also have to address the way we distribute and consume resources. So for me it is all about human behaviours, less about the size of the population, and more about how we live together.

More information on Ian's research

More information on Jane's research

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