In honor of Halloween, here is a fright for you: today is the day, according to one UN estimate, that the world population reached 7 billion. (Estimates vary – the US census bureau puts that date as next March). The population is growing by about a million people every five days. If current trends continue, we’ll see 8 billion people in 15 years and 9 billion people by 2043. That means that, if I am lucky enough to live that long, I will see a tripling of the world population in my lifetime (it was 3 billion in 1960 when I was born).

For this auspicious date I’ve updated my population essay and data spreadsheet with the latest numbers. Enjoy.