Population scenarios suggest unique challenges in the long term —both from rapid growth and sharp decline
As scenario planning consultants involved in strategic foresight, it is no surprise that we have written quite extensively about various aspects of population – size, growth, composition, the difficulty of forecasting, the changeability of forecasts – and the implications of all of the above. There are a number of factors that draw us to the subject: population forecasts – projections of future demographic trends – are fundamental tools for governments, businesses, and organizations attempting to plan for the coming decades. These forecasts, built upon present data, historical trends, and assumptions about birth rates, mortality, and migration, deliver glimpses into possible futures.
But population is simultaneously both an independent variable, a cause of societal change and disruption, and a dependent variable, itself affected by societal change (e.g., an accelerating decline in fertility as a result of urbanization). And unexpected events—on a large enough scale—can dramatically alter demographic patterns. We shall return to explore some of these later. But first let’s assume that population in the longer term will only be affected by large, slowly changing macro forces, and look at what’s in store using data provided by population experts at the Wittgenstein Centre for Demography and Global Human Capital.
Long-Term Global Population Trends: A Mixed Picture
To accommodate at least some of the complexities, the Wittgenstein Centre makes projections allowing for a variety of different future assumptions. The table below shows differences in the projected change in global population between 2025 and 2060 related to alternative assumptions about the pace of economic development, the amount of inequality and the level of migration. The central projection is referred to as ‘medium’ – this is the middle of the road “scenario” that can also be seen as the most likely path for each country. It combines for all countries medium fertility with medium mortality, medium migration, and the Global Education Trend (GET) education scenario.
Clearly “middle of the road” does not mean the same everywhere. Far from it, as the data show. There are several striking features:
- China’s population will fall significantly, and its decline is relatively insensitive to assumptions.
- In contrast, Africa’s population will explode, nearly doubling in all but one of the scenarios.
- Europe’s population will decline and only if migration rates double will it grow, and even then only modestly.
- US population growth is modest and almost entirely dependent on migration.
Unsettling Population Scenarios for 2060
Any one of these as a headline would be attention grabbing, to say the least:
- “China has lost 230 million people”
- “Africa has added 1.25 billion” (Yes, one billion, people since 2025)
- “Europe stagnates as it continues to lose people”
- “U.S. population stalls without immigrants”
But all of them at the same time is almost unthinkable, and yet this is the current, most likely projection. Of course such headlines are unlikely as none of these changes will happen suddenly, but as the combined effects become apparent, they are likely to challenge policy makers and form an increasingly prominent part of economic, political, societal and cultural conversations over the coming decades.
Looking even further ahead toward the end of the century the global population is projected to decline, possibly irreversibly. But perhaps by then trends will have been disrupted – although it will take events on an extremely large scale to have done so.
The most powerful disruptors of population change in recent history have been the introduction and widespread availability of the contraceptive pill, and the One-Child policy in China. Can we imagine plausible events on a similar scale?
What Could Disrupt Current Population Projections?
Several types of large-scale events could significantly alter long-term global and national population projections by fundamentally shifting fertility, mortality, or migration trends. Below are the most plausible categories:
1. Global Pandemic (i.e., worse than COVID-19)
Impacts: Drastically increased mortality; long-term health effects; fear-driven fertility reductions; migration halts.
2. Technological or Biomedical Breakthroughs.
Impacts: Longer lives → higher population; or enhanced fertility → reversal of fertility decline in wealthy nations.
3. Climate Catastrophes
Impacts: Regional population collapse; large-scale internal and/or cross-border migrations; concentrated urban growth or depopulation.
4. Economic or Political Collapse of Major Powers
Impacts: Fertility plunges, emigration surges, or health system failures → altered growth paths in affected and receiving countries.
5. Nuclear or Large-Scale Conflict
Impacts: Sudden, massive mortality; refugee surges; economic breakdowns; prolonged fertility and health system impacts.
6. Policy or Ideological Revolutions
Impacts: Sharp reversal or acceleration of fertility/migration trends depending on context.
7. AI and Automation Societal Transformation
Impacts: Speculation about the evolution of AI focuses on the possibility of exponential increases in productivity and economic growth, and with it the decoupling of the economy from the size of the labor force. So, advanced AI could offset the economic drag of a shrinking population or the costs of explosive population growth.
8. Unknown Unknowns (“Black Swans”)
Impacts: Entirely unpredictable shifts in population structure, survival, or relevance of current demographic models. Meteor hitting the earth? Alien invasion?
So, should emerging population scenarios frighten us?
The short answer is no; there are no pending population crises per se. And in another decade, one or more of the disruptors discussed above may give rise to a yet different population outlook. Population trends move slowly but they are by definition complex and interdependent on developments and cross-impacted in many other dimensions – economic, political, technological, societal, etc.
But looking at population is a productive place to start when thinking about and planning for the future, as all of the foreseeable changes – including enormous growth in Africa, decline in China, and stagnation in advanced economies – and the events that may disrupt them illuminate challenges that will have significant implications for the US and world leadership over the next decade and likely beyond. We best be prepared.
A thought-provoking essay that gets one wondering about all the adaptation that China, for one, will have to go through to secure middle income development status and keep its population healthy, gainfully employed, and happy — as its population falls well below the replacement rate of 2.1%. (It’s now an unbelieveable 1%.) Even with population decline there are serious labor market challenges as automation and AI reduce headcount in both manufacturing and services. A trade war with the US is the last thing Chinese leaders want to contemplate.
Exactly. It’s hard to imagine relationships with China becoming less turbulent – unless of course its domestic challenges can only be addressed with international engagement.
Extracting meaning from such knotted demographic trends runs a risk of chasing endless rabbits, doesn’t it?
This may be one of case in which artificial intelligence might be of use to scenario planners—not for delivering answers but for organizing the problem, rather as disease researchers use AI for studying protein folding.
Indeed Kevin. The issues are knotted together and changes in any one reverberate almost endlessly. AI could well be very useful in proving a clearer picture of the problem(s).
First, let me note how engagingly written this blog is. Most articles on population can be…well…turgid would be a complement. This piece sets a new standard.
As Kevin McDermott noted, easy to chase rabbits on this topic, but I shall indulge that weakness briefly. As is noted in the blog, the cross-impacts of these trends and events provide scary narratives. Of real concern to me: nearly 30% of the global population live within 30 miles (50km) of an ocean coast. About ½ that number live within 6 miles (10km). Sudden ocean rise (let us speculate 10 ft, 3 meters from Greenland warming) which is plausible (probable – maybe not quite yet) within this time frame. But that does not cause just an acute problem – deaths, migration, starvation, economic devastation – but long term chronic problems. The most serious would be pandemics (yes, plural) from loss of health care, potable water, and decent sanitation.
It is like the classic boxer’s right jab, then roundhouse left hook, except its it the global population on the mat.
The sea-level rise you mention would indeed be devastating, although current forecasts are not as dramatic, certainly not by mid-century. But who knows? Forecasts are often wrong, What I find most striking however is how little we hear about the consequences of China’s dramatic population loss and the enormous rise in Africa’s population.