"Teacher! Yesterday was...tree...growing...make new forest day!"
"Oh! You're right. Arbor Day."
I found this video from WeForest, which is cool both because of what they do, and because Stephen Fry narrates it. Also, it's one of those good videos that includes key bits of text from the narration in the video itself, which makes it much easier for my kids to follow along and retain important points.
Did you know that trees made clouds? I didn't!
A good discussion-starter if you're working on environmental issues in your class.
If you want to see other videos I've used in class, visit the Multimedia Monday tag. If you want to save any of these videos for your own personal or pedagogical use, I recommend YouTube Downloader HD.