What is the effect of exponential growth on a population?

1 Answer

Exponential growth means the population will grow by a certain factor every year.

You may also say that the population will grow with a certain percentage every year.

In theory, if the growth factor is constant. the population can reach any size, given time.

Example :
Let's say the population grows with 5% every year, meaning that for every 100 people the difference between births and deaths is 5 in the positive (you can do the same for immigration and emigration).

The growth factor is now 1.05, meaning you multiply the existing population by 1.05 (this is the same as adding 5%). And the next year, etc.

After, say, 10 years you've done this 10 times, so the population will be #1.05^10=1.63# times as high as 10 years ago, and in 15 years it will have more than doubled. With a growth of "only" 2% you will still double your population, but it will take longer (35 years).

You can image the impact on the economy, standard of life, etc.

General formula:
#N=B*g^t#
Where #N#=new sitiation, #B#=start, #g#=growth factor, #t#=number of periods (e.g. years)