This book describes the Ecological Footprint analysis technique, written by its creators. This is the most promising approach to sustainability I've found thus far. It advocates replacing sustainability-as-sacrifice and sustainability-as-moralizing with an empirical approach in which "sustainability" is actually defined and quantified, and our impact on the Earth and environment is measured. This is just a model, and estimates must be used, as it's impossible to know exactly what the human carrying capacity is or what exactly is our impact on the Earth. But it's sufficient to redirect environmental rhetoric toward more useful dialogue, and to help us know exactly what needs to change, and what priority to place on these changes.
I really love the way this book words things. It never says, "environmentally-friendly," for example (as if we're somehow hurting the environment's feelings). It constantly reminds the reader that there is no such thing as an "environment," as something "out there." We ARE the "environment." However, the actual details of this book made my eyes glaze over. Numbers with units like "cubic meter/ha/yr" were bandied about indiscrimately while not going into much detail about how the numbers are arrived at, let alone how we can calculate an ecological footprint ourselves, which is why I read this book in the first place. Then, I guess in an attempt to make this book more accessible, there are useless figures featuring really bad cartoons of a character shaped out of a footprint, with the big toe as his head.