PAI Releases First High-Resolution World Map of Future Population Growth and Decline

May 1, 2006

Washington, DC – Pockets of rural Africa, Latin America and Asia are likely to lose population in the next two decades despite generally increasing density in these regions, a new map of projected future population increase and decline suggests.

Released by Population Action International (PAI), Mapping the Future of World Population is a first-of-its-kind, high-resolution map of projected population change for the year 2025, showing a world with large areas of population loss but overwhelmingly still increasingly filled with people. The map – a collaboration with researchers at the Center for Climate Systems Research at Columbia University – was released in conjunction with a 2006 update of PAI's Web data feature, People in the Balance, which details the relationships of human population with fresh water, cropland and other critical natural resources.

"The technology for mapping population density keeps improving, and we're pushing it a bit further with this map," noted Robert Engelman, PAI's Vice President for Research. "We can’t really 'map the future.' But we can use detailed maps of current population density and the latest country population projections to calculate the most likely locations for population gains and losses worldwide."

Mapped population projections will be of particular interest to conservationists, climate specialists and others who need to know where people will live, and in what numbers, in the decades ahead. The technology may also provide "best guesses" of where and how many people in the future are likely to be vulnerable to natural disasters.

PAI's partners at Columbia University were Dr. Stuart Gaffin and Lee Hachadoorian, now of City University of New York Graduate Center and Hunter College. To produce the map, the researchers extrapolated out to the year 2025 changes in population from 1990 to 1995 that occurred in grid cells about three miles wide at the equator and decreasing in size toward the poles. The researchers selected from two mathematical approaches to arrive at the best and most likely fit with the United Nations' "medium variant" projection for each country's population.

Mapping the Future of World Population indicates that the greatest increases in population density through 2025 are likely to occur in areas of developing countries that are already quite densely populated. The map also projects areas of fairly dramatic depopulation, including much of southern and eastern Europe and Japan. More surprisingly, the map indicates small areas of projected population decline in many regions in which they might be least expected: sub-Saharan Africa, Central and South America, the Philippines, Nepal, Turkey, Cambodia, Burma and Indonesia. Currently, all of these regions have overall populations growing at a modest-to-rapid clip.

"We believe these are mostly rural areas that are experiencing rapid out-migration to urban centers," explained Engelman. "Land degradation in these areas may be making subsistence farming uneconomical even for stable populations."

Despite concerns about population decline in the industrialized world, much more of its land area is projected to experience population growth than decline in the next 20 years. There's little projected decline in North America and almost none in Australia and New Zealand. Modest growth is projected for northwestern Europe despite projected decline elsewhere on that continent. The vast majority of the world's land will have many millions more people in 2025 than today.

"This map is a projection, and Population Action International would be happy if the reality of 2025 is far rosier than what we see here," commented Amy Coen, PAI's President and CEO. "The issue of population is more complex than it was a few decades ago. Where people move and where they settle affects every aspect of their lives, as well as the health of the countries in which they live. This map gives us a glimpse into the future, and the opportunity to create a healthier one while there is still time."