Everyone loves predicting the future, even though some predictions are often well off the mark.

    "Man shall never reach the moon, for such a quantity of gunpowder would be needed as to gravely injure the crew."
    Children's Encyclopaedia, 1926

One of the most agreed on predictions for the future was by astronomer Nikolai Kardashev. He felt that our civilization might progress through four different stages, and that other alien civilizations might be categorized as being in one of those four distinct stages.

A scheme for classifying advanced technological civilizations proposed by Nikolai Kardashev in 1964. He identified three possible types and distinguished between them in terms of the power they could muster for the purposes of interstellar communications.

An image of Kardashev scale projections ranging from 1900 to 2100 on pic below. The projections are off by 0.1 on the kardashev scale. This is graphed against the supportable population and given growth against the supposed technology growth associated the kardashev scale. Projections are made by different ratios of energy production to technology growth for a given level of energy (and technology) against predicted population growth, and new technology production and new energy production needed to support a given population, and the growth of such population. In some projections, if energy production is unable to keep up with population growth, technology levels fall. In some projections, as population growth slows, supposedly increased technology can be produced via the lower amount of energy needed to sustain population growth.

Current status of human civilization
Human civilization is currently somewhere below Type I, as it is able to harness only a portion of the energy that is available on Earth. The current state of human civilization has thus been named Type 0. Although intermediate values were not discussed in Kardashev's original proposal, Carl Sagan argued that they could easily be defined by interpolating and extrapolating the values given above. In 1973, he calculated humanity's civilization type to be 0.7, in relationship to Kardashev's model for Types 0 and I.

Type 0 CivilizationType 0 civilization
Essentially, our civilization. A type 0 civilization has only just begun to tap planetary resources such as solar power, geothermal power and wind power. Most of its power generation is still based on non-renewable fossil fuel resources, for example, oil, coal and natural gases.

Type I civilizationType 1 Civilization
These civilizations can effectively control the entire resources of their planet; they can predict weather patterns and earthquakes very accurately, and even control them using artificially induced greenhouse effects or space-based lasers. A Type 1 Civilization could conceivably halt an ice-age.

Type 2 CivilizationFigure of a Dyson swarm surrounding a star
Type 2 Civilizations have extended their power to their entire Solar System by harnessing the power of their suns through Dyson spheres. Having colonized or at least extensively explored all the planets within their Solar System, they are a largely space-faring race and have already mounted expeditions to other stars using interstellar craft.

Type 3 Civilization
Type 3 CivilizationAt the cusp of their power, type 3 civilizations span entire galaxies having colonized all the stars by wave after wave of interstellar craft. They can harness the power of galaxies. Astrophysicists theorize that this may be done by exploiting the fact that black holes can be used as a source of energy as they slowly evaporate via Hawking radiation. By utilizing the millions of black holes that are believed to reside within galactic nuclei, type 3 civilizations would have sufficient power to conduct truly universe-changing high-energy physics experiments and examine matter down to the Planck length.

At this point, the exact potential of type 3 civilizations becomes unclear due to our hazy knowledge of ultrahigh-energy physics. It is conceivable (as physicists such as Michio Kaku and Lawrence Krauss believe) that such energies could unravel matter down to the super-string length and thus possibly access other dimensions. However, we must stress that this is only informed conjecture and frankly we'll never know what type 3 civilizations will be able to do until we either become one or encounter one.