Today is 8 billion day - but how did we get here?

The global population has hit eight billion, the UN has announced. Demographers chose 15 November to mark this milestone - though it could be up to a year or two on either side.

So, how did we get here and where might we end up?

The UN says the world's population has hit eight billion, just 11 years after passing the seven-billion milestone. But after a big surge in the middle of the 20th Century, population growth is already slowing down and it could take 15 years to reach nine billion and the UN doesn't expect to reach 10 billion until 2080.

This great video from the BBC explains how the global population has reached this milestone and what it might mean for the future.

This article from the BBC looks at the babies selected by the UN to represent the five, six and seven-billionth children - so what can their stories tell us about world population growth?

And although pretty dated now - this video is a great explanation of population growth up to the 7 billion milestone that we reached in 2011...