In 2025, people flock to the beach

Over the next 19 years, the world's population of 6.5 billion will boom by an additional 1 billion to 2 billion people. Researchers from the Earth Institute at Columbia University have tried to project where all those people will live on a new high-resolution map.

The map shows that the number of people living within 60 miles of a coastline will reach 2.75 billion, up 35 percent over 1995 levels. That could be a dangerous trend considering rising sea levels and tumultous weather from the effects of global warming, they say. Moreoever, the largest population growth will happen in developing areas like eastern Asia that are already densely populated.

Populations in Japan and Eastern Europe will drop significantly, however. Several unexpected regions for decline on the map include sub-Saharan Africa, Central and South America, the Philippines, Nepal, Turkey, Cambodia, Burma and Indonesia. These are all areas that have experienced modest to rapid national population growth, according to the researchers.

The project, called Mapping the Future, is a collaboration of the Center for Climate Systems Research (CCSR)--part of the Earth Institute--Hunter College and Population Action International (PAI). Stuart Gaffin, associate research scientist at CCSR and lead scientist on the project, said that the work combines two areas of demography--mapping and long-range, aggregate projections--to better visualize how populations might migrate and why.

The mapping project is different from others in that it displays the projected population for nine million cells distributed globally, rather than figures for the world's 200 countries. The research extrapolates population changes that occurred between 1990 and 1995 out to 2025 in each grid cell.

This new area of spatial analysis and demography is known as "downscaling," and is designed to delivers fine detail on population shifts to fields like conservationists and climate specialists. "We already have a pretty good idea of how the population of individual countries is likely to change in coming years," Gaffin said in a statement.

"This map pushes the frontier on projecting high-resolution, sub-national populations so we can begin to examine how internal population dynamics might play out against other environmental, ecological and socio-economic concerns," he said.