I saw this today on the TreeHugger blog and thought it was a very simple and clever way to look at how to consider the steps to living a more Earth-friendly life. The bottom of the pyramid is the very cheap and easy things one can do to reduce their energy consumption and damage to the environment. As one moves up the pyramid, the options become more and more expensive and difficult. If you're trying to budget in ecologically responsible things in your life, this can be a handy tool.
What do you think?