WASHINGTON ( CNN ) -- The world 's population is forecast to hit 7 billion in 2011 , the vast majority of its growth coming in developing and , in many cases , the poorest nations , a report released Wednesday said . Riders cram into a train last month in New Delhi , India . India 's population is expected to be 1.7 billion by 2050 . A staggering 97 percent of global growth over the next 40 years will happen in Asia , Africa , Latin America and the Caribbean , according to the Population Reference Bureau 's 2009 World Population Data Sheet . `` The great bulk of today 's 1.2 billion youth -- nearly 90 percent -- are in developing countries , '' said Carl Haub , a co-author of the report . Eight in 10 of those youth live in Africa and Asia . `` During the next few decades , these young people will most likely continue the current trend of moving from rural areas to cities in search of education and training opportunities , gainful employment , and adequate health care , '' Haub continued , calling it one of the major social questions of the next few decades . In the developed world , the United States and Canada will account for most of the growth -- half from immigration and half from a natural increase in the population -- births minus deaths , according to the report . High fertility rates and a young population base in the developing world will fuel most of the growth , especially in Africa , where women often give birth to six or seven children over a lifetime , the report says . The number is about two in the United States and 1.5 in Canada . A stark contrast can be drawn between Uganda and Canada , which currently have about 34 million and 31 million residents , respectively . By 2050 , Canada 's population is projected to be 42 million , while Uganda 's is expected to soar to 96 million , more than tripling . `` Even with declining fertility rates in many countries , world population is still growing at a rapid rate , '' said Bill Butz , president of the bureau . `` The increase from 6 billion to 7 billion is likely to take 12 years , as did the increase from 5 billion to 6 billion . Both events are unprecedented in world history . '' By 2050 , India is projected to be the world 's most populous nation at 1.7 billion , overtaking current leader China , which is forecast to hit 1.4 billion . The United States is expected to reach 439 million for No . 3 on the list .
Global population to reach 7 billion in two years , research institute projects . Most growth is occurring in developing and poor nations , study finds . Uganda 's population expected to almost triple by 2050 . India projected to overtake China as most populous country .