Kardaschev types

A classification system for civilizations based upon energy usage.

• Type I civilizations control all available energy on a single planet.
• Type II civilizations control all available energy in a solar system (for example, using Dyson spheres).
• Type III civilizations control all available energy in an entire galaxy.
• Type IV civilizations control all available energy in a complete universe. This obviously requires a cosmology in which baby universes or other exotic constructions are allowed.

The interesting property of this scale is that it avoids any attempt at predicting the exact technologies that any civilization might use since such predictions would undoubtedly be wrong. Instead it focuses on relatively objective physical measurements of the energy usage of a civilization which should be completely independent of technology.

Humans are currently a Type 0 civilization, using less than the full resources of the Earth.

-Back to the Transhumanist Terminology metanode

While I'll agree that the pithy analogies are an excellent conceptual tool, there are actual numbers attached to the Kardaschev Scale.

• Type I: total energy consumption of between 10¹⁶ and 10¹⁷ watts/year. This is a roughly equal to the insolation of earth.
• Type II: total energy consumption of between 10²⁶ and 10²⁷ watts/year. This is roughly equal to the energy output of the sun.
• Type III: total energy consumption of between 10³⁷ and 10³⁸ watts/year This is supposed to be roughly equal to the inferred output of the Milky Way. But to be honest, I don't understand cosmology well enough to know what factors should be considered in making this estimate so I've no way to judge the relative credibility of my (single) source. YMMV.