The Fall: Last Days of Gaia

In the year 2060 terrorists speed up global warming by using terraforming technology, creating a planetwide desert. In 2085 the game starts with the player joining the Government of the New Order as a mercenary. He fights the wasteland gang "Ratskulls" which killed his father and abducted his sister until he begins to question the mission due to intriques and betrayal. Source: Wikipedia, "The Fall: Last Days of Gaia", available under the CC-BY-SA License.