How computer games can save the world?

When I think of Computer Games it doesn't call to mind an educational experience which will cause someone to plant trees, recycle more often, switch to LED lighting, etc. Computer games seem to be more about awesome graphics depicting horrific violence. But a session at the The Green Software Unconference made an interesting point and idea: GAMES will Save the World How?

The session was hosted by Ken Eklund with green21.org which is an initiative attempting to drive the "green" conversation to diverse audiences through its national public television series, online ecosystem and game narrative streams.

Unfortunately I could not be in that talk but the meeting notes say a lot of things in outline form.

Computer games create a virtual environment within which a player can interact with game elements. That's very high level but I think the point is the game doesn't have to be about awesome graphics depicting horrific violence. The game elements can be instructional, for instance it could depict a forest ecosystem and your job is to manage the ecosystem through dozens of generations.

The notes describe a game Ken did about a world without oil. It might have been a fictional scenario where Oil never existed on this planet or it could be a post-Peak oil scenario. In any case it would be very educational to have a SimCity sort of game depicting people living out their lives, but it's a life with oil depletion or life with zero oil. Supposedly it really affected the way people thought about oil.

I have a question reading through the notes.. an idea they may have discussed. What is it about the horrific violence games that make them popular? And if you make a game that's educational and meant to influence opinion towards a green cause, what would get people to come to the game, to play the game, and to play the game long enough so it makes the desired effect?