The 2017 UN world population prospects indicates that the world population is 7.6 billion as of mid-2017 and will reach 8.0 billion in 2020-2024. World population is growing at 1.10% each year and is adding 83 million people each year. This is down from 1.24% per year a decade ago.
There may still be an undercount in several fast growing African nations because of very old census data. It is politically problematic in some countries to have a census. There could also be an undercount in China because of undocumented second and third children.
There should be 7.65 billion people at the end of 2017 and with the various undercounts there could be 7.75 billion.
Adding 83 million each year would put the world population at the end of each year at
2018 7.73 billion 2019 7.82 billion 2020 7.9 billion 2021 7.99 billion (very good chance of hitting 8 billion in 2021) 2022 8.07 billion
A slightly revised undercount or slightly higher fertility and the world population will hit 8.0 billion in 2020 or 2021.
The UN also indicates that the number of people over 60 will be over 1 billion in 2018 and over 2 billion by 2050. Children under 15 years of age currently are about one quarter of the world’s population.
The median age of the world’s population is 30.
This is the medium projection and it forecasts 9.8 billion people in 2050. The “high-variant” projection would have an additional half a child of fertility and the low variant would have a half child less of fertility. Those variants would be plus or minus one billion people in 2050.
In 2012, the medium variant had a projection of 9.6 billion in 2050. So the UN has been revising population forecasts upwards for about the last 10-15 years. The UN demographers had been expecting Africa to be on track for lower fertility. African fertility is declining but not as fast as previous declines in Asia.
India’s population will be higher than China’s population starting around 2024.