Projection of World Population

L. David Roper (
Blacksburg, Virginia 24060


This is an update of the web page including world-population data through 2016.

Fits to the Data

The author has change the approach to fitting world population data (P) to include the chage in population (C). Both population and population change are fitted together, because population change shows changes better. The two data sets are related mathematically by C = dP/dt, so there is an integration constant that relates P to C: P = constant + .

This combined fit to population and population change uses 4 Verhulst functions and an integration constant for population. As shown, it is assumed that the current decline in population change continues.

This shows the fit curve for population change back to 1900.

This shows the fit plus possible negative population growth in the future either due to humans reducing the birth rate or global warming or some other disaster.

Population Theory

World population grow so fast and large because humans discovered how to extract fossil fuels from the earth and obtain energy from those fuels. Without the use of fossil fuels human population would probably have approached an asymptote long before now. As fossil-fuels extraction declines and the only available sources of energy return to solar, the population must at least level off as it appears to be doing, or it must decline, which is probably more likely.

L. David Roper interdisciplinary studies

L. David Roper,