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The future of the world’s population in 4 charts

Tariq Khokhar's picture

Last week, the UN released updated population figures and projections. I just had a chance to go through them and the great key findings document (PDF, 1MB) that accompanies them.

But before I dive in, how accurate are these projections? What kind of track record do UN demographers have? The most comprehensive answer I could find was Nico Keilman’s 2001 paper which Hans Rosling refers to in this video. He notes that in 1958, when the UN projected the population in 2000 to be ~6 Billion (it was then 42 years into the future) they ended up being out by less than 5%. The short answer is: these projections are pretty good.

OK, back to the new data released in 2015: here are some of the trends that stand out for me. Note that I’m using the UN’s regional groupings rather than the World Bank’s

1) The world’s population is projected to reach 11.2 billion in 2100


There are 7.3 billion people alive today and while the world’s population continues to grow, it’s growing more slowly than in the past. We can expect to see an additional billion people added over the next 15 years, and about a billion more 10 years later, reaching a total population of 9.7 billion in 2050.

Population and development: An unfinished agenda

Abdo S. Yazbeck's picture
Health Care Workers
Photo by Dominic Chavez/ World Bank

Forty-five years ago, the World Bank began a major shift in its approach to development.  Prior to the 1970s, the Bank’s overwhelming focus was on infrastructure projects, consistent with our origins as an agency focused on post World War II reconstruction.  The later shift came with recognition that sustained economic development had a lot to do with human development, not just physical development, which led to our first projects on population.   In the early years, these focused  on the Caribbean, North Africa and South and East Asia, and were underpinned by recognition that population dynamics have direct impact on poverty, health, human capital and economic growth. 

What does “urban” mean?

Chandan Deuskar's picture
Follow the author on Twitter: @cd_planner

This aerial view of Hanoi, Vietnam, clearly shows areas of decreasing density between the city and the countryside, making it hard to define the limits of the "urban" area.
Anyone reading this blog is likely to have heard the statistic that ‘over half of the world’s population now lives in urban areas’. This has been the standard opening line of reports and presentations about urbanization since this milestone was supposedly reached in 2008. But what does it really mean?

In everyday usage, terms related to human settlements have vague, shifting meanings. What one person might describe as a small ‘city’ might be a ‘town’ or ‘village’ for someone else; one person’s ‘megacity’ might be a cluster of cities from a different perspective. Similarly, we can usually identify areas that are clearly within a city and others that are outside it, but there is usually a peri-urban area of intermediate density that usually lies between the two, making it hard to define a clear city limit. Formal administrative boundaries may have historic or political meaning, but are rarely aligned with the physical or economic extents of the urban area.

What exactly is a city? It depends who you ask

It turns out there is no standard international definition of an ‘urban’ area or ‘urban’ population. Each country has its own definition, and collects data accordingly. The statistic that 50% of the world’s population is urban is arrived at simply by adding up these incomparable, and sometimes conflicting, definitions.

One Billion Tanzanians, One Billion Ugandans

Anton Dobronogov's picture

It struck me to find out that according to the UN’s official projections, populations of Tanzania and Uganda would exceed one billion people by 2100 (up from 45 and 33 million, respectively, in 2010) if total fertility rates in each of these countries remain constant at their 2010 levels (5.6 and 6.4 children per woman, respectively).

To be sure, this “constant fertility scenario” is not a likely one. For a number of reasons, fertility rates tend to fall as economies develop, and the process of demographic transition from high mortality and high fertility to low mortality and low fertility is already under way in both countries. Still, even under assumption that total fertility rates will gradually decline to about 2 children per woman (and there is no international migration), the UN estimates that there will be 171 million Ugandans and 316 million Tanzanians in 2100.

A new global data network on population and environment

Jed Friedman's picture

Co-authors and I are soon to complete (fingers crossed) some new work on climatic shocks and neo-natal mortality. But our findings are not the topic of this post. Rather I want to discuss the necessary behind-the-scenes data construction work that had to take place before the first regression could be estimated. The work involved the aggregation of fifty plus national level microdata sets (from Demographic and Health Surveys) and then a merger with geo-coded historical weather data (from NOAA).

Cities and PPPs: I’ve got Ulaanbaatar on my mind

David Lawrence's picture
Photo courtesy of

I recently read a quote by Edward Glaeser, an urban economist, in the latest issue of IFC’s quarterly journal on Public-Private Partnerships (PPPs), which caught my attention:

Statistically, there is a near-perfect correlation between urbanization and prosperity among nations. As a country’s urban population rises by 10 percent, the country’s per capita output increases by 30 percent.

Latin America: Putting a human face on health systems

Keith Hansen's picture

Latin America: Crying out for good health systems. Photo: Marie Chantal Messier

It takes a health system to raise a healthy child—or nation. And this is true here in Latin America or anywhere else in the world.

That’s the big message of a small video the Bank has recently launched, featuring an adorable animated newborn named Maya. In it, Maya cries profusely, many times, but her tears are not the sad consequence of disease or discomfort but of the baby feeling well. Maya’s are happy tears –the product of a healthy baby. You can follow her journey into adulthood on her own Facebook page

Earth hits 7 billion mark, Brazil’s clinics provide hope to the poor

Carlos Molina's picture

As the world’s population hits today the 7 billion mark, unleashing mixed emotions across the globe, Latin America can consider itself lucky that overcrowding is not that big of a deal in our neck of the woods.

Or is it? Experts point out that while the region’s share of the world’s population is a mere 8% -or 560 million- a great concern is that the vast majority of those people –up to 75%- live in cities, leading to overstressed basic services, such as healthcare. My colleague James Martone of the Broadcast Unit, went to Northern Brazil to film a project about a community that has found innovative ways to provide healthcare for the poor.

The Seven Billion Mark

Eduard Bos's picture

Photo: Arne Hoel, The World Bank

The UN Population Division has determined that the 7 billion world population mark will be reached today, October 31, 2011. This week’s Economist, the Guardian online, and the New York Times have written on this already, and other news media are following suit. Having produced the World Bank’s demographic projections for some years, and now working as a demographer in the World Bank’s Africa Region, let me add my perspective to the mix.

The approximate date of the world reaching the 7 billion mark is no surprise. When the Bank issued demographic projections back in 1985 (linked to World Development Report 1984– the only one in the series to have specifically focused on the demographic aspects of development), the 7 billion milestone was forecast for early 2011. This is quite close to the current estimate, especially when you consider the projection span of 26 years. At the global level, demographic projections are fairly reliable (but less so for individual countries or small regions).