What are the global population trends?
Population
The world population increased from 3 billion in 1959 to 6 billion by 1999, a doubling that occurred over 40 years. The Census Bureau's latest projections imply that population growth will continue into the 21st century, although more slowly. The world population is projected to grow from 6 billion in 1999 to 9 billion by 2044, an increase of 50 percent that is expected to require 45 years.
Source: US census bureau, International database, http://www.census.gov/ipc/www/idb/worldpopgraph.php, last retrieved Aug 22, 2010
Growth rate
The world population growth rate rose from about 1.5 percent per year from 1950-51 to a peak of over 2 percent in the early 1960s due to reductions in mortality. Growth rates thereafter started to decline due to rising age at marriage as well as increasing availability and use of effective contraceptive methods. Note that changes in population growth have not always been steady. A dip in the growth rate from1959-1960, for instance, was due to the Great Leap Forward in China. During that time, both natural disasters and decreased agricultural output in the wake of massive social reorganization caused China's death rate to rise sharply and its fertility rate to fall by almost half.
Source: US census bureau, International database, http://www.census.gov/ipc/www/idb/worldgrgraph.php, last retrieved Aug 22, 2010
Demographics
In 2025, nearly 2/3 of the population will live in Asia.
30% of the European Union population will be over 65. In 2030, it is expected to have 2 people in age of work per elderly person (compared to 4 people per elderly person today).
International migrations
international migration will develop and without an important inflow of immigrants, EU population will start to decrease as from 2012. If the current trends continue, there will be almost 250 million migrants in the world in 2025 of which 65% will be established in the developed countries.
Population in cities
The cities in developing countries will account for 95% of urban growth in the next 20 years and will shelter almost 4 billion inhabitants in 2025.The number of the inhabitants of slums at world level will double between now and 2025, reaching more than 1.5 billion.
Cities in the North grew by only 30% in the last three decades compared to 400% for those in the south. In 2050, 80% of the world urban population will be in the countries of the South. 11 out of the 20 first megacities (> 10 million inhabitants) in the world will be in Asia.
Source: European Commission report, the world in 2025, http://ec.europa.eu/research/social-sciences/pdf/the-world-in-2025-report_en.pdf