When I was a kid, I worried a lot about what would happen if their was a war. In school, we had those ridiculous drills telling us to "duck and cover". I remember watching a movie on television about an attack. A little boy in the movie looked toward the explosion and was blinded by the flash. It really scared me. I asked my parents what we would do if it happened. They had no real answer other than not to worry about it.
Looking back, it would have been much better if we had just talked about it. Once kids understand the ramifications, even those that are not good, they can better cope with the situation. If kids are worried about 2012, parents should not just dismiss their fears.