The world's population is about to hit a new milestone — 8 billion.
The ABC's data analyst Casey Briggs and ANU demographer Dr Liz Allen answered your questions and unpacked what it means.
You can look back on our expert Q&A in the blog below.
Key events
Live updates
By Jessica Riga
We'll wrap things up here
Thank you so much for joining our expert Q&A today to celebrate the world population nearing 8 billion!
And, of course, a huge thank you to our experts, ANU demographer Dr Liz Allen and ABC data analyst Casey Briggs, for their contributions.
We couldn't get to every single question that was sent in, but we hope you enjoyed today's discussion.
For the record, we're still teetering right on the edge of 8 billion, according to UN projections.
And don't forget, you can join Casey Briggs tonight at 8pm for an ABC News Channel special on world population.
In the meantime, you can download the ABC News app and subscribe to our range of news alerts for the latest news.
We'll see all 8 billion of you next time!
By Jessica Riga
How do we solve these issues?
Wealth distribution, ageism, gender inequality. Massive issues. How do we solve those? Via which mechanisms?
- Christopher
Hi Christopher, thanks for writing in.
Here's what ANU demographer Dr Liz Allen says:
Solving social challenges (especially redressing inequality) is a big endeavour, but doable. It’s doable in our lifetime. We just need the commitment to battle the stubborn and wicked social problems of our time.
I reckon Australia needs a policy vision that sets out a whole-of-government approach to wellbeing. A blueprint for the future we want, with milestones tracking progress, is what we need to start making positive and lasting change.
If all else fails, my go-to is to get angry. Constructively angry. So, maybe we all just need to get angry…constructively.
We also put this to ABC data analyst Casey Briggs and he recalled this quote from Dr Elin Carles-Edwards:
"As a demographer, we're really optimistic people because we've seen massive change over the past 100 years. Everyone's living longer, fewer babies are dying, fewer women are dying. Across a whole range of metrics we're doing better than we did. We've seen lots of small actions creating massive change for people."
By Jessica Riga
What's the magic fertility number?
If fertility rates fall below 2.1 births per woman, the population will fall. Casey Briggs explains.
Remember, you can join Casey Briggs tonight at 8pm for an ABC News Channel special on world population.
By Jessica Riga
How many people do we meet in our lives?
How many people do we meet in our lives?
- John
Hi John, good question! Thanks for asking it.
Here's what ANU demographer Dr Liz Allen says.
It might hard to know how many people we know and will ever meet. We do tend to move a few times over our lives and this might determine how wide our net of people is.
But, did you know that it’s estimated that around 100 billion people have been born, lived and died on this earth?
Ultimately, it really doesn’t matter how many people we meet or know, so long as we have at least one person who provides us with support.
By Jessica Riga
Humans have spread remarkably quickly
But the most rapid increase in our numbers has happened since the Great Depression. Casey Briggs explains.
Want to explore the data in more depth? Join Casey Briggs tonight at 8pm for an ABC News Channel special on world population.
By Emily Sakzewski
In 2023, India will take over China as the world’s most populous country
China has been the country with the largest population for decades, but that's predicted to change next year.
China's population growth has slowed significantly since the 1970s and 1980s with the introduction of the one-child policy under Deng Xiaoping.
The policy was introduced when the population reached 969 million in 1980 and was strictly enforced by the National Health and Family Planning Commission, which fined families who had more than one child.
The policy officially came to a close in 2016 when it was replaced with a two-child policy.
Meanwhile in India, the fertility rate has also fallen in recent decades, but at a rate slower than China's.
As a result, the UN expects India to overtake China as the most populous country in 2023.
By Jessica Riga
The global 'population pyramid' is about to be turned on its head
Can't get enough of the data?
Join ABC analyst Casey Briggs tonight at 8pm for an ABC News Channel special on world population.
Here's a sneak peek!
By Jessica Riga
Would overpopulation or depopulation be worse for society?
Ultimately, would overpopulation be worse for societies, or depopulation as currently predicted? –Hisashi
Hi Hisashi, thanks for writing in. I've put your question to ANU demographer Dr Liz Allen. Here's what she said:
The world population is set to grow at a slower rate over the coming years, with deaths set to outnumber births in about 2080 setting in train population decline.
Population growth or decline aren’t in and of themselves bad things. The key issue is how a population is functioning, and this often gets boiled down to the proportion of the population which is of working-age: is the working-age population sufficient to support the whole population.
One thing is certain, though. Gender equality increases living standards for individuals, families and communities. Trouble is in countries like Australia, there are far too many barriers now blocking young people from achieving their dreams (if they choose) to have children. Removing the barrier for young people in Australia is as simple as addressing gender equality (including accessible and affordability childcare), building job security, ensuring housing affordability, and taking action on climate change.
By Jessica Riga
On deciding whether or not to have children
Why do we still struggle to find love or sexual partners when there are over 8 billion people on this earth? With more people on this planet, has the desire to love, get married, or have sex became less relevant as more people try to compete with each other and face other threats such as climate change that occupy their mind? What are the consequence for human society with this many people? – Thomas
With a huge global population and numerous issues of public concern (climate change, cost of living, access to services etc), is it ethical to start a family when it might exacerbate the already prevalent problems our community faces?
Hi there, thank you both for your questions. Here are some thoughts from the ABC's data analyst Casey Briggs:
I don’t want to give you advice on whether you should start a family, but these questions are certainly things that more and more people are thinking about. One of the experts I spoke to in reporting this story said the ethical considerations of having kids is a topic their students are increasingly bringing up in lectures.
My colleague Angelique Lu has spoke to women who have been grappling with these questions for this excellent story below.
By Emily Sakzewski
Global birth rate from 1950 to 2021
Data shows that by 2100, projected fertility rates in 183 of 195 countries won't be high enough to maintain the current population unless it's compensated by immigration.
A 2021 study published in The Lancet found better access to modern contraception and the education of women and girls has contribued to the decline in fertility.
The study's modelling showed that by 2100 the average number of children a woman delivers over her lifetime will have declined to below replacement level of 2.1 births per woman.
"One important determinant of population growth is the rate of fertility decline in high-fertility countries, particularly those in sub-Saharan Africa. This rate of decline was driven largely by improvements in access to education and modern contraceptives," the study said.
It predicted the largest decline would be seen in those high-fertility countries.
For example in Niger where the fertility rate was the highest in the world in 2017 with an average of seven children, the rate is projected to decline to around 1.8 by 2100.
By Jessica Riga
Fertility slowing as global population grows
The world's population has grown to eight billion but the fertility rates in Australia paint a different picture. ABC reporter Angelique Lu explains.
By Jessica Riga
What does this mean for the future workforce? Which industries will thrive and which will not?
I wonder what this means for the workforce in the future. Which industries will thrive and which will suffer?
- Chris
Hi Chris, thanks for your question.
ANU demographer Dr Liz Allen says "workforce issues differ the world over."
India, for example, is set to experience a rapid economic growth via the demographic divined as the bulk of the population is aged in the peak working ages. Australia is very different.
Australia is confronted with an ageing population and with it a total transformation of the needs of the population (aged care, for example) while ensuring sufficient workers and tax inputs.
Ultimately, Australia doesn’t have the number of people to meet the needs of the workforce. Education and training are the foundation of meeting the current and future workforce needs, but immigration is a vital component also.
With challenges come opportunities. Australia’s workforce is changing and becoming more family friendly. Australia is becoming more global, aided by its migration program.
Healthcare (and related products) is a big boom industry.
Computers haven’t yet put us out of jobs, but even as more work is automated nothing can replace the humanity of a human brain.
By Bridget Judd
The population is growing at a time when we're putting more pressure on the world's natural resources
Why is over population of humans never raised as the source of most of the planets problems including climate change, pollution of air land and sea, quality of life reducing, liss of so many other species and more. – Gael
Thanks for your question, here's Casey Briggs:
Casey: Hi Gael – you’re not the only person to raise this. And yes, the population is growing really fast at a time when we’re putting more and more pressure on the world’s natural resources and biodiversity.
One thing to remember though is that the world’s population growth is slowing down, and it will peak. And there’s not a lot we can do right now to change the trajectory in the coming decades.
Things get a bit more uncertain in the second half of the century, but the next 30 years are basically baked in, because most of the people that will be alive in 30 years are already alive today.
Here’s what John Willmoth from the United Nations told me:
“We can't do a lot about that anyway, especially over the next 30 years, which is the period when we really need to be acting to address the climate crisis. […] If it's a problem, it's a problem that has been solved.”
By Emily Sakzewski
Deaths worldwide, from 1950 to 2021
There were approximately 5 million excess deaths in 2020, and 10 million in 2021 — an increase that can be attributed to the COVID-19 pandemic.
The spike in the late 1950s to 1960 may be attributable to the 1957-1958 influenza pandemic, caused by the H2N2 virus, which was estimated to have caused 1-4 million excess deaths.
By Jessica Riga
What would be better measures of the state of our society?
Why do so many measures of what is apparently good in our societies rely on population data needing to show that our population is growing? What would be better measures of the state/health of our society? –Michelle
Hi Michelle, thanks for your question. We've put it to ANU demographer Dr Liz Allen. Here's what she says:
The typically economic focus on growth (of any kind) as being a good thing tends to miss the more nuanced details of how a population is doing.
Understanding wellbeing is a good basic approach to tracking living standards of populations and can be defined in a whole manner of ways. As a demographer, this is how I approach measuring how societies are progressing; by understanding wellbeing and needs.
I tend to focus more on things like gender equality, health, education, homeownership, and working-age population etc to understanding progress.
By Jessica Riga
Is there an ideal population limit given our natural resources?
Is there an ideal population limit given our natural resources? –Nas
Hi Nas, thanks for writing in. We've put your question to ANU demographer Dr Liz Allen. Here's what she says:
There is no consensus concerning an ideal or maximum population limit, for the world or Australia.
There have been attempts to gauge ideal or optimal population size for specific areas. Carrying capacity is the most commonly cited method seeking to determine, via a mathematical equation, the maximum human population sustainable given natural resources. The calculation of carrying capacity is highly flawed, because it doesn’t factor in innovation and assumes a fixed or constant capacity of an area. Technological innovation has transformed populations and living standards time and time again. Thus, carrying capacity has been debunked.
Carrying capacity has also been associated with the Malthusian theory of population doom. Eugenics and coercive population policies have also been linked to the application of carrying capacity calculation, and Malthusian ideals.
Australia’s carrying capacity has been suggested to be variously 5 million, 15 million, and even 150 million.
I take the stance that wellbeing and sustainable living should always be priorities in matters of population.
By Bridget Judd
Population growth means reshaping the way we think about our societies
With the world's population expected to hit 10 billion in the future, what are some of the challenges facing governments?
Casey Briggs unpacked this one on ABC News a short time ago.
He says it involves a "fundamental reshaping of the way we think about our societies".
Casey: We're going to have a much older average population where a greater share of the population is older. So there's some obvious healthcare and aged care challenges involved in that.
We might need to rethink our taxation system, when you have fewer working people and more people of older retirement ages.
We might need to rethink what work looks like and when we retire. And... how that retirement might look into the future.
The other challenges that we've got are around - well, there's two billion more mouths that will need to be fed in the coming decades. Things like food security, food sustainability, how do you grow food and distribute it to the people that actually need it in a world that is being increasingly impacted by climate change?
A lot of challenges. It's not to say that we won't meet them, but there are certainly a lot of challenges there and we will unpack all of those and more in our special program tonight.
By Emily Sakzewski
This chart shows the world's population rate from 1950 to 2021
Since 2019, the global population growth rate has fallen below 1 per cent.
That's less than half of its peak of 2.3 per cent in the 1960s.
This data comes from the UN's latest release of its World Population Prospects, released in July.
By Bridget Judd
There’s so many different ways the next century could play out, and so much of it is in our hands
Fossil energy resources are singularly responsible for the growth in the human population over the past 70-80 years. We are very likely to see rapidly declining fossil energy use due to depletion and there are really no equivalent alternatives. It is entirely possible the human population will decline much more steeply and sooner than is currently projected. Are demographic projections taking this into account or do they just assume limitless energy and resources? – Peter
Has the predicted decline taken into account possible future catastrophes from climate change? – Lyndal
Thanks for writing in, we've put these to Casey Briggs.
Casey: Both great questions Peter and Lyndal!
It’s not like there’s a specific variable in the population models for “climate change”, no. But indirectly these factors would play into the UN’s forecasts. And there’s quite a bit of uncertainty in the forecasts for the second half of the century, including for some of the reasons you’ve suggested.
The Director of the UN’s Population Division John Willmoth told me that the forecasts use information from every country’s national census, as well as detailed information about deaths and births from nations that have it, plus surveys in some countries.
Even he concedes it’s not perfect data: “Ideally, we would have a census every 10 years for every country, we don't have that. And ideally, we would have complete registration of births and deaths all over the world. We don't have that either.”
Fertility rates are the single biggest driver of population growth, and different forecasts have a major impact on when the world population peaks. For example, a different model from the IHME suggested fertility rates would fall earlier than the UN had estimated, bringing forward the population peak by a couple of decades.
The difficulty is that there’s so many different ways the next century could play out, and so much of it is in our hands. On energy – can we successfully shift to renewables that can replace fossil fuels? How fast can we do it? Will we see increased conflict around the world?
The UN’s chief António Guterres put the warning starkly this week at global COP27 climate talks:
“Our planet is fast approaching tipping points that will make climate chaos irreversible. We are on a highway to climate hell with our foot on the accelerator.”
Will humans get their act together and slam on the brakes?
By Bridget Judd
Young people will be a 'direct witness to one of the most fundamental changes in the world's population'
I just finished Year 12 and I'm entering higher education next year. What are going to be the main challenges for future generations and how will the ongoing trends in population impact us? – Adrian
It's time to start the Q&A, thanks for writing in Adrian!
We've put this one to the ABC's Casey Briggs.
Casey: Congrats Adrian on your graduation!
There’s a very good chance that the world’s population will reach a peak in your lifetime, so you’re going to be a direct witness to one of the most fundamental changes in the world’s population.
Through your career Australia will have a growing number of older people, and that brings with it some tricky policy questions around health, aged care, and tax that our leaders need to think through carefully. Will we shift our thinking around how we budget, and how we value economic growth?
Your kids (if you choose to have any) will have fewer people in their generation than your parents.
At some point all countries will go into population decline. Countries in Europe will be some of the first, and we’ll see a shift in the balance of population – with a greater share of the population in growing regions like India, Pakistan, and sub-saharan Africa. Could that upend international relations?
Unfortunately, you’ll also be seeing more and more of the effects of climate change, so we’re going to need to think about how we limit that as much as possible, adapt to what we can’t prevent, how we grow food sustainable, and what kinds of resources we rely on as the world warms.
