The People of Sparks, Jeanne DuPrau

This second book in the Ember series picks up pretty much exactly where the first book, The City of Ember, left off. Lina and her friend, Doon, have not only found a way out of Ember (through the Pipeworks), but have led the majority of Ember out of the underground and into the post-apocalyptic world above ground. The citizens of Ember are completely naïve to the new world around them, not sure about things as simple as natural light and certain plants, animals, and lifestyles. The Ember-ites come to a city called Sparks that offers to assist them until they are strong enough and knowledgeable enough about their new world to be sustain themselves. Ultimately the city is too populous with Ember relying on the resources of Sparks to survive, even though there is only enough for one to survive. Obviously conflict ensues because of the stress that develops as a result of scarce resources and a huge group of guests who have clearly overstayed their welcome, and it is up to the people of Ember and Sparks to either get along and work together to survive or go down as a collective.

I'm not typically a fan of sequels, but this one is pretty well done. It's an interesting look at the human condition and universal truths such as the inherent desire of a person to survive, and stands as almost a cautionary tale in some ways. The state of the world that the people of Sparks and Ember are living in is a direct result of the overuse of resources and neglect to care for the earth and its resources. This series would serve as an excellent platform upon which to consider world issues like global warming and the threats it poses, as well as what we can do to make changes and move towards becoming a sustainable nation ourselves.