In case you’ve missed it in the news, the world’s population is expected to reach 7 billion in a few weeks time. This came as a bit of a shock to me, as I remembered the 6 billion landmark as being fairly recent (it was actually 1999).
This page on the BBC News website is interesting, if you enter your date of birth it tells you how many people were alive at that time. In my 35 years the world population has grown by just under 3 billion.