Making the invisible visible...
I recently attended a lecture which described science as "making the invisible visible." It's a nice phrase, since it embodies so much of what is progress in our history. Most of the great advances in medicine came from understanding the role that invisible microbes play in making people sick. People now instinctively are more hygenic as they understand what causes illness doesn't have to be something they see.
The New York Times has an article called The Carbon Calculus that describes pricing fuels based on their contribution of CO2 to the atmosphere. This pricing is in economic parlance an externality. Any cost that is not directly captured. Beyond greenhouse gases we don't accurately capture the cost of automobiles in things such as road costs, health costs, etc. It really can be too much.
Other things to consider is the cost of other items, such as mentioned in the article is wine bottles. The argument that glass is heavy and costly but plastic bags and cardboard is actually better.
This notion of capturing the carbon cost is a good way to make the invisible visible.