A good analogy can go a long way. What's great about this clip is that it starts out all cheery and hypothetical. Then here comes the punch line and BAM you're sort of kind of terrified. I know I am.
We've got your attention, so let's note that population growth hasn't been perfectly exponential everywhere on the planet. But growth has without a doubt been explosive, and that means our planet is at risk. We have to do something about this.