Earth: Exodus is an upcoming Setting Book for the Savage Worlds roleplaying system (http://www.peginc.com). Basically, this is a quasi-post-apocalyptic sci-fi setting which takes place on Earth in 2412, almost 100 years after a mass evacuation of the planet.
Essentially, mankind had created a Global Climate Control System which was linked by orbital satellites, and this system was online for over 150 years. Scientists figure out that a long period of Solar Flare activity is likely to disable or destroy the majority of those satellites, which is going to lead to unpredictable climate change and wipe out most of the human population on the planet. The only realistic answer is to build a fleet of starships and evacuate as many people as possible. There are several twists and turns, but ultimately about 90% of the population leaves the planet, and then the proverbial #$%^ hits the fan.
The game setting actually takes place almost 100 years after the Exodus. The Earth is very, very different than it once was. Climate and weather patterns have completely changed, and stable environments are uncommon. A massive desert known as "Anhudo Azoth" actually moves across the face of the planet, often leaving death and destruction behind as it slowly crawls away to a new area. Other bizarre weather patterns and changes are the rule rather than the exception these days.
The people who have been left behind have a lot of struggles and obstacles before them. Pre-Exodus technology is fairly common and often still works, leading to many opportunities for scavengers and explorers who are willing and able to risk the unpredictable weather, the strange animals which have survived and evolved over the past hundred years, and more.
We will be starting a Kickstarter project for this setting as soon as we have some nice content to show off, so keep your eyes peeled for that. Also, open discussion and commentary is very much welcome!
Check out the 'World Notes' tab for the working document on this setting.