After growing very slowly for most of human history, the world's population more than doubled in the last half century, crossing the six billion mark in late 1999. Furthermore, world population is still increasing by about 78 million people a year, despite the trend worldwide towards smaller families. Total population size is likely to continue to grow for at least the next 40 years and by at least another 1.5 billion people. Almost all of this growth is occurring …showed first 75 words of 1468 total…

…showed last 75 words of 1468 total…population will therefore depend on continuing or accelerating socio-economic development in the vast majority of the world's developing countries. A number of factors could hinder the demographic transition, including declining economic growth, persistent poverty, or cultural factors that encourage large family size despite rising prosperity. If the transition were stalled, global population would most probably continue to rise throughout the next century, meaning that world population in 2050 could number anywhere between 8.1 billion and almost 12 billion.