## Human race 2012 Kardashev score

The Kardashev scale is a metric used to grade how advanced some civilization is, in terms of total energy utilization. The usual grading goes from Type I (all the energy of a planet) to Type II (all the energy of a star) to Type III (all the energy of a galaxy) and there are some extrapolations beyond that. Carl Sagan used the values given by Kardashev to interpolate non-integer scores for civilizations, with the following equation

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

where $\displaystyle K$ is the Kardashev score and $\displaystyle P$ is the average power output. A Type I civilization would have $\displaystyle K = 1.0$, Type II would have $\displaystyle K = 2.0$, and so on. So now we need some numbers.

According to a BP overview of worldwide energy consumption (page 40, “Total World”), in 2012 the energy consumption $\displaystyle E$ amounted to 12,476.6 million tonnes of oil equivalent, where a “megatoe” is $\displaystyle 4.476 \times 10^{16}$ joules. Therefore, we get

$\displaystyle P = \frac{E}{t} = \frac{12476.6 \, \mbox{Mtoe} \times 4.476 \times 10^{16} \frac{\mbox{J}}{\mbox{Mtoe}}}{365 \, \mbox{days} \times 24 \frac{\mbox{hours}}{\mbox{day}} \times 3600 \frac{\mbox{s}}{\mbox{hour}}} = 1.771 \times 10^{13} \, \mbox{W}$.

Which when we put into the first equation we get

$\displaystyle K = \frac{\log_{10} 1.771 \times 10^{13} - 6}{10} = 0.7248$.

The Wikipedia page uses 2008 numbers and gets 0.717, so we’ve gone up a few points in the past few years, if these numbers are right. I’d be fairly confident of 0.7, somewhat confident about 0.72, and less-so about 0.725.

EDIT: Using data from the EIA’s database for world total primary energy consumption, I found historical values of:

$\displaystyle K_{1980} = 0.698 \\ K_{1990} = 0.706 \\ K_{2000} = 0.713 \\ K_{2010} = 0.723$