Market failure: The tragedy of the commons

Nice explanatory videos
I like this one best https://www.youtube.com/watch?v=lwaNZgY9PCQ but you may prefer https://www.youtube.com/watch?v=MLirNeu-A8I
This is longer (and fairly right wing) but has some good points
https://www.youtube.com/watch?v=B0vmP7HoFI4