The Cost of Free Parking

I've often felt that the car and how we use it often impacts us in negative ways. I spotted a discussion from a UCLA scientist on what he indicates is the high cost of free parking. The basic analysis is mathematical, but the conclusion is really clear, and we can see in in may of our hometowns.
Do you have a shopping mall near you? How much of the malls land is dedicated to parking and how much to stores? If I had to guess, it's probably 2/3 or so for parking and just a third for the stores. That means that the stores are paying taxes land that just gets used part of the time (and for a non-revenue purpose) which raises your cost of goods.
Perhaps more significantly, all that paved land means that that land is not covered with a crop nor with trees, either of which oxygenate the air and reduce absorbtion of solar heat. Should we destroy all parking lots? No! Should we look at improved public transit and/or using the bicycle to do some of our shopping? Yes!
The story that I saw can be found here: http://www.npr.org/templates/story/story.php?storyId=4622062