The world stopped growing about 1988... and has only grown older since.
Global births, per five year periods, according to the UN.
Births and UN medium and low variant estimates through 2040...plus my best estimate of the most likely births. Despite the significantly larger (older) total population, births continue to languish and appear set to decline. Since 2000, total births are declining everywhere except Africa.
Assuming the UN medium variant...chart below shows births by Africa, S. Asia (India, Pakistan, Afghanistan, Bangladesh, Bhutan, Nepal, Iran, Sri Lanka) and the world minus Africa / S. Asia..
Or, looking at births by GNI (gross national income) per capita. Only the poorest nations are having more children, while all other nations (by income) are having significantly fewer (high income and upper middle) or stalling (lower middle income nations).
The next charts below show the child bearing populations, from high, upper middle, lower middle, and low income countries (based on 2016 GNI per capita, detailed by the World Bank HERE).
For the high income countries, peak annual growth in the child bearing population took place as of 1963, but the total child bearing population didn't peak until 2009. The population capable of child birth will continue falling through at least 2030 and likely far longer.
The upper middle income countries peak annual growth took place as of 1985 and the total child bearing population also turned negative in 2009...and again will continue declining indefinitely.
Lower middle income countries peak annual child bearing population growth took place in 2000 and annual and total growth continues to decelerate.
Low income countries annual child bearing population growth is still rising and not likely to peak until around 2040, while the total child bearing population will continue rising until perhaps 2060.
Finally, the best proxy for economic activity is energy consumption. The chart below shows actual and EIA estimate energy consumption through 2040. Clearly, the population growth in S. Asia (lower middle income) and particularly in Africa (low income nations) has not and is not anticipated to result in significant energy consumption or economic activity.
What that looks like as a %.
Somebody should write about this stuff.