How far will global population rise? Researchers can’t agree

Recommendable! Will world population peek at 11 billion from current roughly 8 billion? 

Is government population size control necessary? Definitely not!

Is it necessary or desirable to maintain a fertility rate (about 2.1 births per woman) at population replacement level at the national or some other level? This is at least controversial.

They say demography is destiny! The size of the population has in the past featured prominently in power politics!

Fear mongering and alarmism still persists!

In the late 1960s, we were alarmed by the so called and mostly debunked  overpopulation time bomb hypothesis by Paul R. Ehrlich, a Stanford University professor. His infamous book was published by the famous Sierra Club associated with the progressive movement! 

Recommendable!

Before that there was the population crisis described by Thomas Robert Malthus in 1798 stating that population growth could outpace agricultural production leading to starvation and worse. Well that did not happen!

There are at least two major trends at work that have influenced world population for the past 100 years or so:

1. Thanks to better living standards and medical treatments people live longer lives
2. For various voluntary and involuntary reasons people have less children per family or household than in previous times

How these two major trends work out nobody knows for sure. 

Will we have artificial wombs (ex utero embryos, see e.g. here, here, here) in the next 30 years or so. Quite possible that human reproduction will see dramatic changes going forward! 

Will there be humanoid robots or intelligent robots in the next 20 years or so. Quite possible!

"The UN says world population will plateau at 10.9 billion by the end of the century. The other groups forecast earlier and smaller peaks, with global population reaching 9.7 billion by 2070 and then declining."

How far will global population rise? Researchers can’t agree The United Nations forecasts that nearly 11 billion people will be living on Earth at the end of the century, but other demographic research groups project that population will peak earlier and at a much lower level.