to last billions of years. You yourself think that projecting the tens of millions place 64 years in the future is an absurd number of significant digits. How m

to last billions of years. You yourself think that projecting the tens of millions place 64 years in the future is an absurd number of significant digits. How many significant digits do you think is appropriate in a time frame 100M years longer? Even the UN itself only purports to project population trends until 2300, which is far short of a billion years, as hubristic as it is. Also, the UN projections have some unjustified assumptions. From page 7, under section C: >Over the long run, total fertility is projected to settle at 1.85 children per woman in each country—in between the current rate for Northern America (which is just below replacement level) and the rate for Europe (which is currently well below). This figure is somewhat arbitrary In the longer run they expect the growth rate of all countries to stabilize at 0: >The eventually similar growth between more developed and less developed regions is produced by similar long-range assumptions, especially the assumptions that fertility will fall in all countries below replacement (in the medium scenario) and rebound to replacement after a period largely similar across countries of a century or so. Starting their fertility declines later, less developed regions will reach low fertility levels after more developed regions but also stay at these levels until a later date. Of course population stabilizes at a rate not too much higher than the present rate if you assume fertility rates converge around the replacement level. Garbage in, garbage out.