Children vs Happiness

Ron Bailey goes there. Matt dissents. Jonah Lehrer thinks it depends on what you mean by happy. But children are definitely not green:

Your net carbon impact depends far more on the number of children you will have than any other variable; remember good environmentalism uses a zero rate of discount. So people with no biological children should be allowed to fly a lot and people with lots of biological children should not get to fly so much at all.