Winner stole my idea!
In my sci-fi universe, Yellowstone erupts, causing a volcanic winter in the whole northern hemisphere. Because climate belts move south, the contries in Africa and the Middle East experience a wetter climate and a subsequent population increase, whilst southeastern Asia, largely uneffected by the eruption, also becomes a world power. The EU splits in half between the Germanic countries to the north and the Romance countries to the south. Russia was broken up in WWIII about a century beforehand into the Republic of Russia (Eastern Europe) and the Russian Federation (Siberia), whilst China has expanded to include central Asia and Indochina.
Both the middle east and east Asia later experience massive revolutions, bringing two enormous super-states, the UME (United Middle East) and the Republic of Indochina, to the forefront of world affairs. A major war breaks out between the Northern and Southern EUs, ending in a titanic orbital bombardment of the North Sea, completely destroying Britain, the low countries and southern Scandinavia, and causing global temperatures to plummet even lower. More and more countries join the UME and Indochina to escape the destructive climate changes. A second war between northern and southern Europe begins, this time started by the south in an attempt to reunite the continent, but the two superpowers intervene and conquer southern Europe before the Australian-built
Excalibur Orion starship can begin bombing the north.
After hundreds of years of expansion, the two superpowers fuse with eachother, forming The Union, which later takes control of the entire world, letting the age of galactic expansion and exploration begin...
Key
Blue: USA and allies, minor allies light blue
Red: China (collapsing)
Pink: Chinese allies
Darkish red: the Golden Circle, a league of socialist states in latin America
Orange, blue-green and dark yellow: the Middle Eastern Treaty Organisations, formed by the USA and China after WWIII. The Centralian League (dark yellow) has expanded to fill a lot of the land controlled by China before the disaster.
Dark Green: The Arabian Revolution, the fledgling UME
Medium Green: The 'Pax Islamica' countries, a group of largely neutral East Asian Islamic states, including Pakistan, Bangladesh and Indonesia.
Brown: The rather transient Mongolian Empire, which rose to power during the chaos caused by climate changes in Northern Asia. It will soon be absorbed by Indochina.
Purple and yellow: The Northern and Southern European Unions. Russia and eastern Europe have aligned with the South.
Greeny-yellow: The Latin Revival Movement.
Dark Greeny-yellow: The African Union.
Grey: Neutral, includes several important states such as the Baikal Republic, Amazonia which is trying to hold back both the Golden Circle and latin Revival, and the American Empire in the central parts of the former USA.
Dark Grey: Uninhabited or broken into countless tiny 'statelets' and tribal groups. These regions are in complete turmoil and war is constant.