From one of my children's eighth grade math books, fifteen years ago.
Who needs a sophisticated scientific model, when you can prove AGW using common household items? That's why I switched to compact fluorescents. The globe doesn't heat up nearly as much.
This was in a school textbook? Good grief.
I saw a video a while back with Al Gore trying to pull a similar stunt, using a large glass jug.
The Earth doesn't have a plastic or glass cover around it to trap heat. Greenhouses have a plastic or glass cover to trap heat. Clouds don't trap heat. Gases don't trap heat. There is no such thing as a "Greenhouse Gas".
Did you write a pleasant letter to both your child's school and the textbook publisher?