Property rights

When reading on Mises today, I got to an interesting comment on the article The Wind and Wave Theory of Property . This person who commented was talking about property rihts to liquids and gases.

I think that this is something we are still missing and have not accounted for.

How could we assign property rights to liquids and gases?

I know you have these days all the emissions trading, EPA, etc..., we can 'buy' a property on the Moon, but no one is selling certificates to a gallon of clean air for example that one would own and destroy according to his/her own likeness.

If we did have property rights to air and water, would people care for them more?

I think they would... I take care of my solid properties, would I take care of my liquid & gas? Sure! Also, in a market for air, where people would have to pay for using it, would the state of our atmosphere improve? Would we have more 'providers' of clean air?

I know, these are just random questions that popped up in my head, but think about them! Wouldn't the market for air make things better? How about China (or other developing nations)? Perhaps its trade surplus would decrease even faster if it were to buy clean water and air from other countries...