World population will be around 15-25 billion in 2100 and will increase through 2200 because of African fertility, life extension and other technology


Via Next Big Future:

The United Nations (UN) recently released population projections based on data until 2012 and a Bayesian probabilistic methodology. Analysis of these data reveals that, contrary to previous literature, the world population is unlikely to stop growing this century. There is an 80% probability that world population, now 7.2 billion people, will increase to between 9.6 billion and 12.3 billion in 2100. This uncertainty is much smaller than the range from the traditional UN high and low variants. Much of the increase is expected to happen in Africa, in part due to higher fertility rates and a recent slowdown in the pace of fertility decline. Also, the ratio of working-age people to older people is likely to decline substantially in all countries, even those that currently have young populations.

There is only a 30% chance of population peaking by 2100. This is even without considering radical life extension or any other turnaround in human fertility.

African fertility alone means world population will not peak by 2100. The old world population forecast will flatten at 9-10 billion before 2100 is done and wrong

Here I describe how the world of 2100 and 2200 will have a lot more people, efficient urbanization in megacities with robotic cars and turbolifts and easy access to space and substantial colonization. Energy and food will not be constraints.

I think 2100 will see a population around 20 billion and 2200 a population in the solar system in the 40-80 billion range.

What could boost population growth ?

* radical life extension for fewer deaths
* lower cost and more effective in vitro fertilization. About 16-20% of couples who want children cannot have them
* if technology in the post-2050 timeframe delivers cheap access to space (orbit and solar system), material abundance from nanotechnology and other technology and abundant energy from nuclear fusion, molten salt fission, advanced solar power and space based solar power, then there could be population and wealth growth without adverse impacts even if population increased hundreds of times beyond current levels

if Africa’s birthrate stayed at current levels and did not drop at all then world population would be about 20-25 billion in 2100.

The extreme longevity scenarios could add 1 billion, 3 billion or 6 billion people to projections.
1 billion would be the difference between the 2010 and 2012 African fertility adjustment.
3 billion would be the difference between 2000 and 2015 African fertility adjustments.
6 billion would be like a worldwide fertility increase of about 0.5 children per couple.

Later in this article I discuss how we can scale food production.

I have also previously looked at scaling nuclear power.

Deep burn nuclear power options –
* fast neutron breeder reactors with onsite or offsite reprocessing of fuel can close the fuel cycle and eliminate nuclear waste (unburned fuel)
* molten salt reactors (like Terrestrial Energy) can increase the power derived from existing uranium by six times

Various reactors from China and Terrestrial Energy and others can be factory mass produced.

Continue reading.