In the snowy Alpine town of Davos, here to take part in the World Economic Forum’s Annual Meeting, John Green, author of bestselling novel The Fault in Our Stars, answers a series of questions from his Facebook followers. Watch him as he’s grilled on topics as diverse as tax and technology, global warming and what inspired him to start writing.

And if you'd like to know why the word "millennial" makes him cringe, read his article on the subject of youth culture here.