Personally I'm not much a player of computer games but probably they can be used for environmental education. In a first investigation I found lincity and Real Life, please check their usefulness by yourself.
lincity build & maintain a city/country. You are required to build and maintain a city. You must feed, house, provide jobs and goods for your residents. You can build a sustainable economy with the help of renewable energy and recycling, or you can go for broke and build rockets to escape from a pollution ridden and resource starved planet, it's up to you. Due to the finite resources available in any one place, this is not a game that you can leave for long periods of time. This game is similar to the commercial simulation game with a similar name. This package provides files common to both the X and SVGALIB versions of the game.