Humanity's Expansion Into Space

By 2225, humanity has spread across the solar system. People have reached the eight planets and their moons, the asteroids, and even the distant Edgeworth-Kuiper belt.

Independent nations and autonomous territories have already formed on the Moon, Mars, and throughout the Main Belt.Even Mercury, Venus, and the moons of Jupiter and Saturn have now become home to colonies designed to endure the harshest of environments.

Earth

Climate change driven by global warming has worsened, rapidly shrinking Earth's habitable regions.

Japan has been hit particularly hard by rising sea levels, and the capital's functions were moved inland in the latter half of the 22nd century. Most economically valuable parts of the former metropolitan area were spared from submersion by extensive coastal defenses, allowing them to survive as "islands" protected by levees. But in 2220, a catastrophic breach known as the Great Flood devastated the area, forcing its complete abandonment. The once-thriving metropolis is now the "Old Capital," a ruined city slowly disappearing beneath the waves.

The Moon

Although under the jurisdiction of the United Earth, the Moon is a federation of cities with its own culture and a high degree of autonomy.
It is one of the wealthiest regions in the solar system, boasting the highest GDP per capita.
In practice, the Moon is governed by a massive conglomerate known as the Luna Dynasty. Residents are either its employees or temporary workers employed by subcontractors.
The governing body is non-democratic and operates through shareholder meetings. This has given rise to a stratified society in which workers who do not own shares are excluded from the decision-making process.
The lunar capital is in Shackleton Crater, near the Moon's south pole.
The Moon is also endowed with many natural resources. Helium -3, used as fusion fuel, and helium-4, used in superfluid applications, are recovered from its surface regolith, while mining operations extract a wide variety of minerals and other resources.