At TEDxSydney 2025 on Friday 9 May, Professor Bradshaw from Flinders University presented modelling that shows a smaller global population is more likely to experience more economic stability and face fewer environmental challenges.
One of fourteen speakers presenting new thinking on big issues, his data describes the effects of unequal population growth and booming consumption of the Earth’s ‘biocapacity’.
“Think of the world as a giant piggy bank. Even though you might have a healthy balance now allowing you to live comfortably, if each fortnight you take out much more than you put in, eventually you’ll go broke. We might not yet be in ‘the red’, but we’re headed that way fast,” says Professor Bradshaw.
“If we look at the per capita consumption since the late 1960s, the average per-person consumption continues to rise at 0.41 GJ per person per year. All our efforts to avert this trend have failed so far,” he says.
“We’re now consuming 1.7 Earths per year, and if everyone in the world consumed like Australians, that figure rises to over 3.5 Earths per year. Why does this trend continue despite the pressing need for changes?”
Using machine-learning models to analyse whether population size or energy consumption contributes more to climate change, Professor Bradshaw will show that population is by far the dominant driver.
“Population growth is not equal everywhere. As early as 2040, Sub-Saharan Africa is projected to dominate growth, and by 2100, over one-third of the children on Earth will be born in Sub-Saharan Africa,” Professor Bradshaw says.
“Unfortunately, Africa is also the continent most vulnerable to the impacts of climate change, unlike Australia, where our wealth will buffer us to some extent,” he says.
“The people who will suffer the most from our collective consumption are therefore the poorest and already most vulnerable.”
In 2024, more than 120 million people were forcibly displaced from their homes, of which 43 million became refugees. His presentation will show that:
- In Africa, every 1% increase in population growth increases the number of refugees by 3-5 times, meaning that by ignoring climate change, famine, and warfare, at least 80-120 million refugees will be produced in Africa alone by 2100.
- Current refugee crises are therefore only the tip of the iceberg.
Professor Bradshaw says this evidence points to the need for big changes in consumerism in advanced and developing countries.
“We also need to ensure everyone can make their own decisions about family size by empowering women globally, and ensuring unlimited access to high-quality, free, non-coercive, and culturally sensitive family-planning services.”
At Flinders University, we are dedicated to finding solutions to complex challenges with research that matters. In a groundbreaking initiative, we asked 30,000 Australians from across the nation to voice the problems that matter to them the most in their local communities, resulting in The Flinders Wicked Problems Report. Read more here.
