It's a 500-pound gorilla that Robert Criss, Ph.D., professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, sees standing on the speaker's dais at political rallies, debates and campaigns. Its name is population growth.

Record numbers of skilled workers migrating to Australia have helped make immigration account for more than half of the country's latest population growth.

Sub-Saharan Africa has been experiencing phenomenal population growth since the beginning of the XXth Century, following several centuries of population stagnation attributable to the slave trade and colonization. The region’s population in fact increased from 100 million in 1900 to 770 million in 2005.

Immigrants population in Canada have grown four times faster with one in five people in the country last year was born in another country, the highest proportion since the 1930s.

China’s efforts to control population growth in the present may cause problems for the county’s senior citizens in the future.

The impact of HIV in Zimbabwe since the early 1980s is explored in new research published this week in the journal PNAS.

The population of India is likely to reach around 1.5 billion by 2025, according to a United Nations Economic and Social Commission for Asia and the Pacific (ESCAP) projection.

Chinese authorities have liberalized the country's birth-control policy allowing urban families to have two children in some circumstances, the Xinhua news agency quoted a senior official at the family planning commission as saying Wednesday.

More than half of humanity – 3.3 billion people – will be living in cities by 2008 and by 2030, some 5 billion will live there, according to a U.N. report set to be released Wednesday.

Resentment toward China's one-child policy has led to a second round of violent protests in southwestern China's Guangxi Province. Joseph Popiolkowski reports from Hong Kong that peasants there are seeking refunds of fines imposed on them for having more children than allowed.

Bulgaria's population has dropped by 1 million to 7.7 million since the end of communist rule in 1989, a nearly catastrophic decrease in such a small country.

Every year, millions of people worldwide are displaced because of natural or industrial disasters or social upheaval. Reliable data on the numbers, characteristics, and locations of these displaced populations can bolster humanitarian relief efforts and subsequent recovery programs. Conversely, the absence of such information can hinder the prompt delivery of aid and impact the survival and recovery of affected groups.