A ballooning world population, projected to hit 10 billion around 2060, is raising public concerns, according to a new study by the University of Southampton.
The research into public perceptions of population growth shows people are worried the increase will create moderate-to-high risks, with concerns focussing on food and water shortages, species extinctions and other catastrophic consequences.
"When the global human population reached seven billion in late 2011, it attracted a lot of media attention and generated a wealth of related discourse among academics," says Dr Ian Dawson of the Southampton Business School's Centre for Risk Research at the University of Southampton.
He adds: "Although much discussion was held about global population growth's potentially adverse effects, I wasn't aware of any studies that had attempted to assess the extent to which the public shared these concerns."
In response, Dr Dawson, together with his colleague Professor Johnnie Johnson, undertook a new study into public risk perceptions regarding global population growth - supported by the University of Southampton's Annual Adventures in Research fund.
The researchers conducted a telephone survey of 300 residents, aged 18 and over, in England, Northern Ireland, Scotland and Wales. Their 47-question survey was 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.
A key finding was that 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. Dr Dawson comments: "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."
Respondents who perceived medium-to-high risks were concerned about ecological damage, resource shortages and violent conflict. In addition, respondents felt the worst effects from a more crowded world would be more likely to occur in the mid-21st century and most likely to be experienced by the world's poorest people.
Approximately half of those who took part in the survey believed that governments rather than individuals or communities 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. Dr Dawson says: "While the present study found that many younger people perceived the risk of global population growth as relatively high, it could be seen as reassuring that the study 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."
Dr Dawson also notes: "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."
In Dr Dawson's view, 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.
Explore further: Experts assess the impact of climate change on public health
Ian G. J. Dawson et al. Does Size Matter? A Study of Risk Perceptions of Global Population Growth, Risk Analysis (2016). DOI: 10.1111/risa.12576