[Life cycle assessments (LCA)](http://en.wikipedia.org/wiki/Life_cycle_assessment) are one of the most important tools in reducing unsustainability. They enable designers and managers to determine which of several product or service options will create the least environmental impact. They are not perfect, but can point to the most impactful aspects of a product over its entire life cycle. Slate did an LCA comparing credit card use to paying cash.
>
> What’s the most environmentally friendly way to spend my money—cash or credit card? Credit cards are made out of plastic, which I know I’m supposed to avoid. But it can’t be good for the planet to make all that cash and truck it around the country. …
>
> Ah, cash or credit—the million-dollar question. As far as the Lantern can tell, no one has published a cradle-to-grave analysis of either a dollar bill or a credit card. (Funny, the financial industry must have other things on its mind.) So we’ll have to do the best we can with some back-of-the-envelope calculations.
>
I won’t tell you the outcome because I think that is not the most interesting feature of this story. You can find the answer in the article. The real story is the use of either cash or credit cards to fuel consumption. To do a full LCA one should include the objects being purchased. And that is where the real impact is to be found. Whatever is bought will almost certainly add to the unsustainability of the natural world. And consumption itself is a key culprit in the unsustainability of humankind, leading to *having* rather than *being*. It would be very interesting and helpful to those seeking to create sustainability to develop an LCA framework that could tell how much *being* is lost for each dollar spent to satisfy the need to have more of something. Money spent authentically to take care of one’s set of concerns wouldn’t enter into this calculation.