Earth in the Balance
When I teach the physics topics moments, c.g. and stability, I tie in a conservation message. This is how:
I give a broom to a student and ask him to balance it vertically on one of his fingers. He would usually be able to do it with ease.
Next, I ask him to look at only the finger with which he is balancing the broom. He certainly cannot balance the broom anymore, because he is now not able to see the shifting and tilting of the whole broom.
The conservation message is: the natural world, our Earth, has been more or less in a state of stable equilibrium for a long period of time. There has been no extreme fluctuations of climate, no extreme sea-level rises and falls for many, many years, and this has helped life thrive on Earth. What humans have been doing in the past decades is upsetting the balance and we are pushing it towards the tipping point. To help re-gain balnce, we must think globally (looking at the whole broom), and act locally (adjusting the finger).