You can calculate your ecological footprint at http://www.myfootprint.org/. The statement at the end about how many worlds we would need if everyone lived like us really makes you think. I've only recently realised that the more we in industrialised countries consume the less there is for others in the third world. Who invented the term "third world" anyway? It makes you think that they are on a different planet with less resources and our over consumption is disconnected from their under consumption. Quite convenient really... the reality is the opposite. Our wealth allows us to buy the resources and work hours of the third world for next to nothing and leave the people there to starve.