Humanity has done its best to destroy itself, but didn't succeed completely -- a few plucky individuals have survived and have banded together to rebuild society... It's not an uncommon theme; in fact post-apocalyptic tales are a whole sub-genre of science fiction, with recent films like the Terminator, Matrix, and, of course, the Mad Max series bringing them to the mainstream. These darker tales can be fun, exciting, and even enlightening.

What's new about the genre, however, is the number of such stories aimed at kids. Jeanne DuPrau's "Books of Ember" series, for example, coming to the big screen soon and featuring Bill Murray, is about a group of kids who have to figure out how to survive and save their civilization. It's aimed at pre-teens. Even Pixar's Wall-E is a sort of post-apocalyptic tale, with the title character doggedly trying to clean up a world too polluted for humans to live in.

So are these darker tales appropriate fodder for kids? "We have more ways of ending the world than we had before," explains DuPrau. "These are big, hard truths that are facing kids, and they need to know these things."

"There's a direct connection between things [kids] may do and the end of the world," notes author Michael Grant, whose novel "Gone" tells the story of a world where everyone over the age of fourteen has disappeared and the kids are left to fend for themselves. "When I was a kid hiding under the desk from Russian missiles, no one ever said, 'Here, Michael, here's what we need to do to avoid that'."

In reading books like this, I always focused on the adventure of post-disaster survival, rather than the lessons to be learned from the disasters and ensuing chaos, but perhaps kids need these lessons more these days. We do have a lot hanging over our heads now -- economic collapse, war, political instability, global climate change -- so perhaps kids do need an outlet for dealing with the word as it is today.