It took thousands of years for the global population to hit 5 billion, which happened in 1987. Some 32 years later, we're closing in on 8 billion. This explosive growth concerns leaders at the United Nations, who created World Population Day [wikipedia.org] in 1989 to raise awareness about the problems caused by overpopulation. The holiday is observed annually on July 11. Some areas are actually losing population According to the UN, 27 countries or areas have seen their populations shrink by 1 percent or more since 2010. This drop is caused by sustained lower levels of fertility, most notably in countries like China amd[sic] Japan. In fact the global fertility rate fell from 3.2 births per woman in 1990 to 2.5 in 2019 and is projected to decline further. But these shrinkages are dwarfed by population booms in other regions. The population of sub-Saharan Africa, for example, is projected to double by 2050.
The Guardian - Global population of eight billion and growing: we can’t go on like this [theguardian.com]
Crucially, the vast majority of the extra 3 billion human beings that could be added to Earth’s population will be born in Africa. Today there are about 1.2 billion Africans. By 2100, there will be more than 4 billion. Our growing population crisis therefore needs to be tackled there as a priority: by boosting women’s rights, by making contraception easily available and by improving education for all. The remarks of President Magufuli suggest that this is going to be a very hard task. Nor have the actions of Donald Trump’s White House helped. By slashing funds to international birth control programmes, the US is now undermining hopes of limiting Africa’s population growth.