22: What's the cost of rain water?

What if you had to pay for the air you breath and the rain water that comes from the earth? We really seem to take these items for granted along with the natural capital of the earth. Pavan Sukhdev’s talk at TEDGlobal 2011 - he states that  "Every day, we use materials from the earth without thinking, for free (like air and water). But what if we had to pay for their true value: would it make us more careful about what we use and what we waste?"