According to the United Nations' World Population Prospects report:
world population is currently growing by approximately 74 million
people per year. Current United Nations predictions estimate that the
world population will reach 9.0 billion around 2050, assuming a decrease
in average fertility rate from 2.5 down to 2.0.
all growth will take place in the less developed regions, where today's
5.3 billion population of underdeveloped countries is expected to
increase to 7.8 billion in 2050. By contrast, the population of the more
developed regions will remain mostly unchanged, at 1.2 billion. An
exception is the United States population, which is expected to increase
by 44% from 2008 to 2050.