HISTORY
Despite advances in solar and other renewable technology, most of the world's 9.6 billion inhabitants were woefully underprepared for the Peak Oil crisis of the 2050's. Many of the planet's resources aside from oil had already been stretched incredibly thin, but the wheels didn't quite come off the global system until first world nations suddenly found themselves seriously short of food, water, and energy.
The United States fell into full scale civil war as did the Russian Federation and several other nations. China and the European Union nominally held things together with harsh totalitarian policies. The Middle East, Northern Africa, and much of Central Asia erupted into a localized nuclear war. Plagues, some likely the result of covert biowarfare attacks, some due to loss of antibiotics' efficacy, decimated the global population.
By 2080 the human population had plummeted to 2.3 billion. In that year, however, a glimmer of hope came in the form of an announcement by a group calling itself the Cascadian Liberation Front. They had discovered the key to fusion power and were willing to share it freely with the world to end the energy crisis. A few years later it was revealed that they had also discovered a means of faster-than-light travel and had been secretly exploring other stellar systems.
By 2100, six other major factions had developed warp drives and a new space race was underway. Currently, Earth's population is about 3 billion, while the colony worlds are collectively home to about 16.25 million, or about half a percent of the total human population. The promised future benefits to humanity from these colonies is not entirely satisfactory to many who feel they've been left behind while tens of trillions of credits are invested in off-world development.