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Africa’s Demographic Multiplication

What will influence the future growth of Africa’s population — and why does this matter to the world as a whole?

June 13, 2011

What will influence the future growth of Africa's population — and why does this matter to the world as a whole?

About 200,000 years ago, a relatively small population of Homo sapiens grew out of eastern Africa and began its historic migration to neighboring parts of the African continent and then onto other major regions of the world. Some 2,000 years ago, the human population — estimated at approximately 300 million — had expanded globally, with the result that no region of the world could be considered “empty.”

Despite extremely harsh living conditions and periods in which death rates outpaced high birth rates, the world’s population managed to reach one billion near the start of the 19th century. At that time, Africa’s population is estimated to have numbered about 107 million, or about 11% of humanity.

When the world population reached the two billion mark in 1927, Africa’s population had grown to about 170 million, but its percentage of the whole had declined to less than 9%. As a result of declining death rates and comparatively higher birth rates, the world population grew at an unprecedented pace over the next 71 years, peaking at a rate close to 2.1% in the late 1960s, thereby tripling in size to six billion inhabitants. Africa’s population, however, grew even more rapidly than the rest of the world, more than quadrupling to 774 million and thus increasing its share of the world population to 13%.

Today, Africa’s population stands at one billion, or nearly 15% of the world population. Due to continuing high birth rates (close to five children per woman) and comparatively lower death rates (life expectancy at birth is 56 years), the population of Africa continues to grow rapidly. While the average annual growth rate for the entire continent is around 2.3%, even higher rates of growth — in excess of 3%, implying a doubling of the population within a generation — are observed in countries such as Mali, Niger and Uganda, whose average fertility rates exceed six children per woman.

Assuming a moderate decline in current fertility levels to the UN’s medium variant of 2.8 children per woman by 2050, Africa’s current population is expected to double to 2.1 billion by mid-century. At this level, the continent would account for nearly a quarter of the world’s population.

And by the close of the 21st century, when the average fertility rate for the continent is assumed to have fallen to the replacement level of 2.1 children per woman, Africa is projected to have a population close to 3.6 billion people, representing 35% of the estimated world population of 10.1 billion.

Regional variations

Closer examination of projected growth rates shows considerable variation across the five major regions of Africa. At one extreme are the comparatively lower-fertility populations of southern and northern Africa, which by the end of the century are expected to increase by 10% and 60%, respectively. At the other extreme is middle Africa, whose population is projected to triple by 2100, and eastern and western Africa, whose current populations of 324 million and 304 million, respectively, are projected to more than quadruple, with each having 1.4 billion people by 2100.

Further appreciation of Africa’s past and expected future population growth may be gained by comparison with neighboring Europe. During the 19th century and most of the 20th, Europe’s population exceeded Africa’s by a large margin (see the accompanying figure). Since then, however, Africa’s population has not only exceeded Europe’s, but the demographic gap between the two continents has been rapidly widening.

Europe’s future population is projected to decline because of below-replacement fertility rates combined with insufficient compensatory immigration. But the population of African nations will continue to increase rapidly. As a result, according to the UN’s medium-range projection, the African population is expected to be nearly three times as large as Europe’s by mid-century — and five times larger than Europe’s by the end of the 21st century.

Data Source: United Nations Population Division

Certainly, other demographic scenarios for Africa’s future population may be envisioned. For example, fertility rates could decline more rapidly by reaching a half child below the replacement level by 2100 (the UN’s low variant), or decline more slowly by rising to a half child above replacement by 2100 (the high variant). Consequently, the projected populations by the century’s end would be 2.4 billion and 5.2 billion, respectively, quite different in either case from the medium variant’s projection of 3.6 billion.

Two other highly unlikely, yet instructive, scenarios worthy of examination assume that fertility rates remain unchanged from present levels (the UN’s constant variant) or fall instantly to the replacement level (the instant replacement variant). If Africa’s fertility rates were to remain unchanged over the coming decades, the population of the continent would grow extremely rapidly, reaching three billion by 2050 — and an incredible 15 billion by 2100, or about 15 times Africa’s current population. At the other extreme, if fertility rates were to fall instantly to replacement levels, Africa’s population would continue to increase due to its young age-structure (half the population is less than 20 years old), growing to 1.5 billion in 2050 — and 1.8 billion in 2100.

Among the African continent’s 55 countries, only one currently has a population exceeding 100 million: Nigeria, at 158 million. When Nigeria reaches 390 million at mid-century, it will be joined by four other countries in the over-100 million group: the Democratic Republic of Congo, Ethiopia, Tanzania and Egypt. Before the end of the century, six additional countries are projected to join the club: Uganda, Kenya, Zambia, Niger, Malawi and Sudan. The aggregate population of these 11 nations is expected to reach 2.4 billion by 2100, representing about a quarter of the world’s population at that time. Moreover, Nigeria is expected to grow to 730 million by century’s end, making it a good deal larger than Europe’s projected population of 675 million.

Another important group of African countries are the 33 nations on the UN’s list of Least Developed Countries (LDC). These comparatively poor African countries have a combined population of 510 million, accounting for half of the continent’s current population. (Ethiopia is the largest of these nations, with a population of 83 million, followed by the Democratic Republic of Congo at 66 million.) Due to their relatively high rate of natural increase — in excess of 2% — the projected population of Africa’s 33 LDCs by the close of the century is 2.2 billion, or slightly more than a fifth of the world’s population at that time.

Confronting Africa’s development challenges

While the UN’s medium-, high- and low-variant population projections are likely scenarios, other future demographic outcomes are of course possible. Nevertheless, evidence from the recent past — a tripling of the African population during the second half of the 20th century — and continuing high rates of fertility plainly confirm Africa’s potential for extraordinary demographic growth in the future.

Some may choose to ignore these population projections for Africa or simply dismiss them as nothing more than mechanical exercises in demographic multiplication. To do so, however, would be a grave mistake with serious implications not only for Africans but also for many others across the globe. Fully recognizing and duly addressing likely future demographic trends are critical components in effectively confronting Africa’s numerous development challenges.

Globally, it now seems likely that Africa will be the last continent to advance through the demographic transition — that is, the progression from high to low rates of birth and death. The pace of Africa’s demographic transition may turn out to proceed relatively quickly, as has been observed in developing countries such as Algeria, Iran and Vietnam.

Alternatively, however, the demographic transition in Africa may move slowly or even stall, as has happened in the past in countries such as Egypt and Kenya. In order to avoid this undesirable outcome, the international community can play an important role in facilitating the demographic transition to low death and birth rates. By virtually any measure, the costs of international assistance to Africa aimed at advancing the continent’s growing population expeditiously through the demographic transition are small — and the resulting benefits are undeniably enormous for families and nations.

More on this topic


When the world population hit two billion in 1927, Africa accounted for less than 9%. By the end of the 1990s, Africa's share of the world population of six billion had risen to 13%.

During the 19th century and most of the 20th, Europe's population exceeded Africa's by a large margin. Since then, Africa's population has not only exceeded Europe's, but the gap has widened.

Evidence from the recent past and continuing high fertility rates confirm Africa's potential for extraordinary demographic growth in the future.