A adventure game about saving the world from the impending climate cataclysm.

A game about influence a star system to for a enduring federation. Have mechanics about pollution, life quality and toxic waste bobardment.

A game with strong environmental thematic, where the elite live on a ship and the rest of the world is dying from overpopulation and climate changes.

A very good and cute point and click that teaches about ecosystem. The whole game takes places on a single tree that you must save from an unkow force.

It takes places on a post-apocalypse future caused by nukes. The game involved a salvaging and rebuilding of the world. Nice turn-based combat.

Another game that takes place on post-apocalypse future caused by nukes. A good FPS/RPG.

A game about social engineering, where by making laws, taxes, etc you can change and see the effects on your country. Environment is a part of the game.

Fate of the World is a PC strategy game that simulates the real social and environmental impact of global climate change over the next 200 years - Devs

A city building game with mechanic like use of land, pollution, water and sewer systems, importance of public transportations, etc...

A nice 4x game that shows the how the fight for natural resources happens. Also have game mechanics of pollution and population control.