what could the world population around 5000 B.C. be?

Question

Today it´s about 6,7 billion
1970 it was about 4 billion
1915 it was baout 1,6 billion
so if we go back in history with a calculaton based on these numbers, it´s hard to believe that people lived anywhere before 2000 B.C at all. How do you explain this?

O.K. If it´s an exponantial function that explains it, then that very function should be striving against 0 at some point. In other words there must be an era with the least population like only a couple of people, so when??

Answer 1

not only is the population increasing, the rate of increase is increasing (and is the rate at which the rate of increase increases too... etc etc.)
added to this at some points in history the population of the world was not increasing.
The world population was probably a couple of tens of thousands of people.

Answer 2

Its very easy to explain. population growth is exponential. That is, the more people on earth, the faster the rate of population growth. Since the growth of population is not linear, the time periods are not relevant. For example, in the period 1970-2007, 37 years, the population increased by 2.7 billion. But in the period 1915-1970, 55 years, the population only increased by 2.4 billion.

Additionally, the exponential growth has been interrupted a few times, the Tuva extinction event of 74,000 years ago nearly killled all humans.

I expect the agenda behind your question is the absurd notion that god created the earth 6000 years ago.

Sorry, the numeric evidence you present above, if it is true, argues for exactly the opposite conclusion.

Answer 3

Using population figures for these periods (1915 - today) to have a backward population projection to 5000 B.C. or for that matter to any period prior to man's control of his environment will give a false figure. Long term population growth rate depends on the target population's ability to survive and grow in his environment. I suppose in prehistoric times, the different species populating earth were competing on a "level playing field" and their respective populations were in equilibrium with respect to each other. Under this conditions, man's population will be very much lower than today's level. As man developed his ability to control his environment, the equilibrium was disturbed in man's favor and his population growth rate soared to the level that it is now. Perhaps, at some future time, a major depopulation event will revisit earth (HIV, SARS, Avian flu, meteorite or a nuclear war or Al Gore's worst case climate change scenario) and the equilibrium will be established once more. I hope tho' that will happen beyond the lifetimes of Al's great, great, great grandchildern.

Answer 4

Easy. It is following an exponential curve with Time on the X Axis and Population on the Y Axis. This is generalized, since it doesn't account for natural and man-made phenomena such as plagues and wars, but it works well for a first approximation. I must assume that you have never studied higher mathematics or you would have recognized this pattern immediently.