Earth hour revisited

My kids and I participated in Earth Hour last night. When I told them about it, I found that they had no clue what I was talking about. To be summed up in my son's question, "if we turn off the lights, does the earth warm up?" So I spent the hour talking to them a little about what global warming is and why it's important. I mentioned ice caps and sea level rising and weather patterns changing. I think they understood a little.
Kids pick up on things so fast I just assumed that had heard of global warming just a little bit. I read a lot on the topic and hope they start reading as well. Don't assume your kid know all about something. Sometimes it's just bits and pieces.
There are a lot of critics of Earth Hour out there (just read the comments on their web site) but I think it's a great tool for raising awareness and my family has decided to participate every week. It's a chance to slow down, talk to your kids, explain a little more of your personal philosophy.
It was fun!