Kardashev scale

 The Kardashev scale is a method of measuring a civilization 's level of technological advancement based on the amount of energy it is able to use. The measure was proposed by  Soviet   astronomer  Nikolai  Kardashev  in 1964.

The scale is hypothetical , and regards energy consumption on a cosmic  scale. Various extensions of the scale have since been proposed, including a wider range of power levels (types 0, IV through VI) and the use of metrics other than pure power.

Categories 

The Kardashev scale has three designated categories, these are:

• A Type I civilization, also called a planetary civilization , can use and store all of the energy available on its planet. 
• A Type II civilization, also called a stellar  civilization , can use and control energy at the scale of its planetary system.
• A Type III civilization, also called a  galactic civilization , can control energy at the scale of its entire host galaxy . 

Type I

Technological level of a civilization that is "close to the level presently attained on Earth, with energy consumption at ≈4×10¹⁹ erg/sec" (4×10¹² watts). Currently, the civilization of Type I is usually defined as one that can harness all the energy that falls on a planet from its parent star (for Earth–Sun system, this value is close to 1.74×10¹⁷ watts), which is about four orders of magnitude  higher than the amount presently attained on Earth, with energy consumption at ≈2×10¹³ watts. The astronomer Guillermo A. Lemarchand stated this as a level near contemporary terrestrial civilization with an energy capability equivalent to the solar insolation on Earth, between 10¹⁶ and 10¹⁷ watts.

Type II

A civilization capable of harnessing the energy radiated by its own star—for example, the stage of successful construction of a Dyson sphere  or Matrioshka  brain —with energy consumption at ≈4×10³³ erg/sec. Lemarchand stated this as a civilization capable of using and channeling the entire radiation output of its star. The energy use would then be comparable to the luminosity of the Sun, about 4×10³³ erg/sec (4×10²⁶ Watts ).

Type III

A civilization in possession of energy at the scale of its own galaxy , with energy consumption at ≈4×10⁴⁴ erg/sec. Lemarchand stated this as a civilization with access to the power comparable to the luminosity of the entire Milky Way  galaxy, about 4×10⁴⁴ erg/sec (4×10³⁷ watts).

Kardashev believed that a Type 4 civilization was impossible, so he did not go past Type 3. However, new types (0, IV, V, VI) have been proposed.

Current situation of human civilization 

At the current time, humanity has not yet reached Type I civilization status. Physicist and futurist Michio Kaku suggested that, if humans increase their energy consumption at an average rate of 3 percent each year, they may attain Type I status in 100–200 years, Type II status in a few thousand years, and Type III status in 100,000 to a million years.

Carl Sagan  suggested defining intermediate values (not considered in Kardashev's original scale) by interpolating and extrapolating  the values given above for types I (10¹⁶ W), II (10²⁶ W) and III (10³⁶ W), which would produce the formula

${\displaystyle K={\frac {\log _{10}P-6}{10}}}$,

where value K is a civilization's Kardashev rating and P is the power it uses, in watts. Using this extrapolation, a "Type 0" civilization, not defined by Kardashev, would control about 1 MW of power, and humanity's civilization type as of 1973 was about 0.7 (apparently using 10 terawatt (TW) as the value for 1970s humanity).

In 2019, the total World energy consumption was 14864.9 Mtoe  (175,249 TWh), equivalent to an average power consumption of 20.0 TW or 0.73 on Sagan's interpolated Kardashev scale.