[sytelus]

As population is one of the indicative of productivity (although a weak one), you can see how many big events were driven by population growth. For example,

- During World War II, US had more people then Germany, France and UK combined. This certainly enabled deployment of massive armies on many front and huge amount of weapon production.

- Japan's population suddenly started rising and overtook many western countries. Its increased productivity might be the reason why this tiny country felt it can take on the world.

- India and China are odd balls. India had massive population since very early times compared to European countries.

-Somewhere in 1870, US population crossed a threshold and became the most populated western country.

-Population for 2100 AD is estimated at 10 billion.