The classic eco-learning game is the Stabilization Wedges one from Princeton.
It’s an (offline) activity that invites players to brainstorm ways to stabilize carbon emissions with a strategic combination of existing technologies.
The technologies — which are geared toward efficiency, decarbonization of power and fuel, and the health of our forests and agriculture — are envisioned as wedges that together will add up to a healthy pie slice of carbon not released into the atmosphere. Check out this introduction to the concept.
Not surprisingly, the Princeton project is supported by:

