Yesterday I bought a book on Earth System analysis that looks extremely interesting: http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=10316
It's an edited collection of papers from the 91st Dahlem Workshop on Earth System Analysis for Sustainability held in Berlin, May 25-30, 2003. To quote from the front jacket:
"Earth System Analysis for Sustainability uses an integrated systems approach to provide a panoramic view of planetary dynamics since the inception of life some four billion years ago and to identify principles for responsible management of the global environment in the future."
It seems to me that it is an important goal to understand the Earth system and right now I feel like I want to work in this area!