Washington: The world`s population is expected to reach 8-billion mark by 2025 and would further increase up to 9.4 billion in 40 years from now but India will creep up to 1.7 billion by 2050, US experts have said.
The current population of the world is 6.8 billion, while India has a staggering graph of 1.2 billion, a place behind China with 1.3 billion.
Africa`s population will be growing most quickly. The humans in the continent by 2050 will double to reach 2.1 billion, US Population Reference Bureau said.
Asia`s population makes 4.2 billion now, and may add 1.3 billion by 2050. However, the growth will depend mainly on demographic situations in India and China.
Europe will be "most likely the first region ever where the population will decline long-term due to low birth level, first of all in Eastern Europe and Russia," the research said.
Presently, there are 738 million Europeans and by 2050 there may remain only 702 million.
Russia`s population is expected to go down to 117 million by 2050 from the current level of 142 million.
As for the USA, the present population makes 310 million. By 2050, it is likely to grow up to 399 million, or even 458 million, depending upon immigrations.
The experts believe that by 2050 the US will be the only `first world` country among the world`s top 10 leaders in population.
Present-day leaders are: China, India, the USA, Indonesia (235 million), Brazil (193 million), Pakistan (185 million), Bangladesh (164 million), Nigeria (158 million), Russia and Japan (127 million).
American experts forecast that by 2050 the same countries will keep first eight positions, though the order may change, while the last two positions will be taken by Ethiopia and the Democratic Republic of Congo.