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Bulletin of the World Health Organization

Print version ISSN 0042-9686

Bull World Health Organ vol.79 n.5 Genebra Jan. 2001

http://dx.doi.org/10.1590/S0042-96862001000500020 

News


The world in 2050: more crowded, urban and aged

The world’s population — with today’s 6.1 billion already more than twice the 1950 figure — is likely to grow by another 3 billion in the next half-century, according to a recently released UN projection. Most of the population growth will occur in the less developed countries of Africa and Asia, despite the staggering death toll of the AIDS epidemic in these countries. In contrast, populations in all but a few industrialized countries will remain stable or even shrink. What’s more, medical progress will allow people to live longer and thus steadily increase the percentage of retirees in the years to come. These are the conclusions of World Population Prospects: the 2000 Revision, the sixteenth round of global demographic estimates and projections made by the UN Population Division since 1950.

Altogether, Mr Joseph Chamie, director of the UN Population Division that compiles the population projections, told the Bulletin ‘‘the world’s population will be very different in 50 years. It will be substantially larger, especially in the developing countries, significantly older and much more urbanized.’’

The world’s population is currently growing at a rate of 1.2%, or 77 million people, per year with six countries accounting for half of the growth: India (21%), China (12%), Pakistan (5%), Nigeria (4%), Bangladesh (4%), and Indonesia (3%). Although fertility rates are coming down in every region and in virtually every country of the world, Chamie points out, by 2050 the overall figure is anticipated to swell to 9.3 billion, and nearly nine of every ten people will be living in a developing country — one out of six in India alone, which will replace China as the most populous nation. Taken together, the population of the world’s less developed nations is expected to grow from 4.9 billion to 8.1 billion. In sub-Saharan Africa, the number of people could even triple.

But this is only one side of the coin. For the more developed countries as a whole, population growth is likely soon to come to a standstill at the current 1.2 billion level, according to the UN projection. Notable exceptions, however, are several industrialized countries, such as Australia, Canada and the US, that are projected to be at least a third larger by 2050 than they are today. By mid-century the populations of 39 developed countries are likely to be even smaller than today, e.g. Japan and Germany by 14%, Italy and Hungary by 25%, and countries of the former Soviet Union by 30–40%, leading to a shift in balance. Fifty years ago, when Europe claimed about 20% of the world’s population, Africa amounted to just 8%. In 50 years, however, Africa will have three times as many people as Europe, even though AIDS is anticipated to cut Africa’s population growth by 15%.

‘‘The engine that determines these differences is the vast difference in fertility rates (between less developed and industrialized countries),’’ says Chamie. In virtually all countries of the more developed regions fertility is currently below the replacement level of 2.1 children per woman — the level needed to ensure that a population will replace itself in the long run. Countries with the lowest fertility rates include Bulgaria, China, Spain (all 1.1) and Italy (1.2), while Niger (8.0), Somalia (7.25) and Angola (7.2) top the high-fertility roster.

A noteworthy exception among major industrial nations is the US, expected to grow from 283 million today to nearly 400 million at mid-century. By then, the US will be the only developed country among the world’s 20 most populous nations. In 1950, at least half of the top 10 were industrial nations. About 70% of population growth in the US will be due to immigration. Without migration, the populations of more developed regions as a whole would start declining in 2003 rather than in 2025, the UN report notes.

But the Earth is not only going to be much more crowded: the UN projection also predicts that the industrialized world — most European countries, plus Australia, Canada, Japan, New Zealand, and the US — will be confronted with an ageing population. Globally, ‘‘we will see a tripling in the number of people 60 years or older’’, increasing from 606 million today to nearly 2 billion by 2050, says Chamie. In more developed regions, people 60 or over currently constitute about 20% of the population. In 50 years, they will account for 33%. In Europe that figure could even jump to 37%.

With fewer people in the workforce and more people living off retirement funds and pensions, an ever older population will represent a major strain for social security systems, Mr Paul Hewitt, project director for the Global Aging Initiative at the Center for Strategic and International Studies, commented to the Bulletin. ‘‘An ageing population is probably the main challenge for the world economy in the next century. Soon the industrial world will face chronic labour shortages and shrinking populations. Retirement as we know it will probably cease to exist in a number of countries,’’ he says.

The UN’s Chamie agrees. ‘‘Now is the time to prepare,’’ he says. ‘‘I offer people three pieces of advice: Prepare for your retirement and old age, prepare for your retirement and old age, and prepare for your retirement and old age.’’

Michael Hagmann, Zurich, Switzerland