Kardashev scale, our future

Kardashev scale
From Wikipedia

Kardashev scale projections ranging from 1900 to 2100.The Kardashev scale is a general method of classifying how technologically advanced a civilization is, first proposed in 1964 by the Soviet astronomer Nikolai Kardashev. It had three categories, based on the amount of usable energy a civilization has at its disposal and increasing logarithmically:

Type I — A civilization that is able to harness all of the power available on a single planet, approximately 1016 W. The actual figure is quite variable; Earth specifically has an available power of 1.74×1017 W (174 petawatts). Kardashev's original definition was 4×1012 W. (Kardashev had originally defined Type I as a "technological level close to the level presently attained on earth", "presently" meaning 1964.)
Type II — A civilization that is able to harness all of the power available from a single star, approximately 1026 W. Again, this figure is variable; the Sun outputs approximately 3.86×1026 W. Kardashev's original definition was 4×1026 W.
Type III — A civilization that is able to harness all of the power available from a single galaxy, approximately 1036 W. This figure is extremely variable, since galaxies vary widely in size. Kardashev's original definition was 4×1037 W.
All such civilizations are purely hypothetical at this point. However, the Kardashev scale is of use to SETI researchers, science fiction authors, and futurists as a theoretical framework.
To put the amount of energy conjectured by this scale into perspective, consider that the ten-second-long burst of neutrinos that follows a supernova releases roughly 1046 joules (100 foes).[1] This is roughly equivalent to 1,000 times the amount of energy that Kardashev speculated would be harnessed in a year by a Type III civilization.

An image of Kardashev scale projections ranging from 1900 to 2100. 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 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.

Usage and examples
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.

A possible method by which Earth can advance to a Type I civilization is to begin the heavy use of ocean thermal energy conversion, wind turbines and tidal power to obtain the energy received by Earth's oceans from the Sun. However, there is no known way to successfully utilize the full potential of Earth's energy production without complete coating of the surface with man made structures. In the near and medium future, this is an impossibility given the current lifestyle of humanity. Currently, we are already "harnessing" Earth's production through our dependence upon ecosystem services, which may prove more efficient and sustainable than our own technology well into the future. If we choose never to fully substitute synthetics for nature's services on this planet, we may still achieve a Type I civilization by assuring that Earth's ecosystem services are maximally functional. A simpler and far less intrusive method would be to place solar collectors with sufficient surface area into orbit.
A hypothetical Type II civilization might employ a Dyson sphere or other similar construct in order to utilize all of the energy output by a star, or perhaps more exotic means such as feeding stellar mass into a black hole to generate usable energy. Alternatively, it may occupy a large number of solar systems, absorbing a small but significant fraction of the output of each individual star. A Type III civilization might use the same techniques employed by a Type II civilization, applied to all of the stars of one or more galaxies individually, or perhaps might use other mechanisms not yet proposed.

Kardashev scale - Wikipedia