"People look at a tree and think it comes out of the ground, that plants grow out of the ground, " he says, but "if you ask, where does the substance [of the tree] come from? You find out ... trees come out of the air!"

https://m.youtube.com/watch?v=ITpDrdtGAmo 

 I was frantically searching for this several months ago, thanks for sharing 

 I'm always trying to find something that I swear just saw... I should put "Googling Things on the Internet" on my resume