Population growth: context in a few critical graphs

Population projections that talk of very high growth are welcomed by some parts of the business community and many governments. Others warn that the numbers and speed of growth will fast outpace our ability to provide the necessary social and other infrastructure required to maintain the quality of life that attracted people in the first place.

Rarely though does either side of this discussion provide some context to numbers so that we can arrive at our own conclusions. With that in mind, here are some graphs and comparisons that might help. You can draw your own conclusions.

(CLICK ON ANY OF THE GRAPHS TO ENLARGE)

This graph (above) shows a range of global cities often mentioned as comparison cities in discussions about Australian urbanism. It's a random selection and not exhaustive. It shows that the predicted population increases for Australia's largest cities are generally on a par with or exceeding the growth of these cities – nearly all of which are much larger in total population than Australian cities. The exception is Tokyo, which is shrinking.

This is the same data but this time showing the increases in population as a percentage rather than as a raw number. In this comparison, tTThis graph is helpful to show the speed and scale at which a city's population is predicted to grow.

In this graph, for comparison's sake, I have added in some mega cities in developing parts of the world such as India and Africa. Much of the world's growth in population will come from the sub-continent and from Africa. India will overtake China as the world's most populous country. The African population will surge. Lagos in Nigeria, for example, will grow by 17 million people in the same time our cities grow by between 2 and 4 million.

Looking at these growth rates as percentages however shows that the rate of growth in Australian cities is equal to or near to the rate of growth of Delhi, Mumbai and Lagos. There are some very obvious differences in housing, social infrastructure, quality of life, regulatory and governance frameworks and a range of other metrics which makes our cities very different from these.

Let's now look at Southeast Queensland. The latest revision of the SEQ Regional Plan includes some updates of population projections together with some forecast job increases (which are promised to be reviewed). Putting the population and jobs growth into the same graph allows us to see that there is an apparent imbalance between areas that are predicted to grow the most in terms of population, but which are not anointed with comparable jobs growth. This will invariably mean that more people will need to commute greater distances for work than if jobs were provided closer to where they are expected to live.

A closer drill down into the detail comes from the Queensland Government Statistician's Office, which released detailed population projects in June 2023. This graph shows where within the inner city of Brisbane the population is expected to change, and by how much, in the 2021-2046 period.

This is the same graph but showing the percentage increases. This graph is helpful to understand the speed and scale of growth by small area. The CBD (Brisbane City) for example is expected to grow by 160%, while other areas will more than double.

This is an image of 443 Queen Street – which when completed will provide 264 apartments. If we allow a modest 10% vacancy rate (apartments locked up by owners and not available for letting), and multiply the balance by a conservative 1.6 people on average per apartment (we are told there will be many more single person households so there could be less than 1.6 in the future), that gives a total population for this tower of 380 people. With Brisbane's CBD predicted to grow by 22,500 people (see graph above) that means we will need the equivalent of 60 more of these in the CBD for those predictions to have effect.

Last one! Here are the regional population predictions for 2021-2046. This graph shows the forecast increases in population by region. I have added a couple of lines to show how these predicted increases compare to the current populations of Rockhampton and Ipswich, just for context.

So, what did you conclude? Some will be excited by the infrastructure challenge. We need not only houses, but schools, hospitals, libraries, water, energy, roads, parks and open space and more. Plus workplaces of course. And protection of the environment.

Others will worry that, if we struggle to find houses for people and with tent cities popping up around the region, we should slow this rate of growth. Longer hospital wait lists, growing school class sizes, rising congestion, environmental pressures – these could be some of the things we should try avoid they will say.

Others again will question the numbers themselves. Some of these predictions seem to lack a reality check. Can we even find, for example, sites for 60 more towers like 443 Queen Street in the CBD? Let alone what many of the other numbers will require in terms of sites for housing, for schools, workplaces, hospitals, and the rest across the region.

It's important that predictions like those contained in these numbers are fully understood for context and impact. More than anything else, they will reshape the regions and cities in which we live.

They are however just predictions based on public policy settings and expectations. They are not fate.