The theme of EarthStock is "Sustainability - the Future is Now", which in its seemingly simple wording is a very complex and insight full theme: considering the complexity of human societies and our planet, the present action determine the future, and only if we realize the aspect we want to see in the future now, there will be a future as we envision it. The theme also involves "sustainability" and I will try to show you that in the interaction of the sophisticated beings we humans are and the complex system our planet is "sustainability" is not a given characteristics. In fact, in human history "sustainability" is a rather young concept, which has come to popularity over the last few decades only. It comes along in various shades, with the most prominent, and the one likely to survive being "Sustainable Development".