The Kardashev Scale
The Kardashev scale is a method of measuring a civilization's level of technological advancement. This logorithmic scale is only theoretical and in terms of an actual civilization highly speculative; however, it puts energy consumption of an entire civilization in a cosmic perspective. It was first proposed in 1964 by the Russian astronomer Nikolai Kardashev. The scale has three designated categories called Type I, II, and III, also known as K1, K2, and K3. These are based on the amount of usable energy a civilization has at its disposal, and the degree of space colonization.
A K1 (Type I) civilization has harnessed the full energy potential of a single planet. On Earth the mastery of the planet's resources equate to an energy output of approximately 10^16 to 10^17W.
This energy output is sustained, meaning that burning up all non-renewable energy sources in one year to achieve the required level of output does not mark a society as K1.
A K2 (Type II) civilization has harnessed the full energy potential of a solar system. This translates to an energy output of approximately 4×10^26W, or roughly 4,000,000,000 times as much energy as a K1 civilization.
A K3 (Type III) civilization has harnessed the full energy potential of an entire galaxy. The energy output of such a civilization is approximately 4×10^37W, or roughly 10,000,000,000 times greater than a K2 civilization.
Where Are We?
As of 2011, the global total energy production was approximately 1.5x10^13W, putting human civilization somewhere around 0.72 on the Kardashev Scale. This gives us a rank of K0 (Type 0).
The difference between the current global energy production levels and the energy output of a K1 civilization is by a factor of approximately 6000. We have a long way to go.