The Kardashev Scale is a concept for measuring the evolutionary state of a civilization in terms of its capability to use energy. You can easily grasp what it is about here on Wikipedia . Kardashev himself, a Russian Cosmonaut who invented it, presented the scale while talking about the possibilities for civilizations to communicate intra- and inter-galactically. He argued that any type-2 civilization would be able to communicate throughout the known universe by sending out strong enough signals in all directions.

Why should we deal with such aloof concepts at all? Because, in my opinion, the world is in urgent need of visions for a common future that encompass all of humankind. And, of course, because it’s fun.

Physicists like Carl Sagan and Michio Kaku made the scale more popular. Sagan even came up with an interpolation formula to transform the discrete scale of type 1, type 2, type 3 into a continuous one. According to Sagan’s suggestion, today humanity scores roughly 0.72.

Let us revise the scale quickly so everyone is on the same page. A type 1 civilization is commonly thought to be able to harness all energy coming from its “parent-star” (in our case the sun) onto its planet’s surface. That would be around 1016 Watts for Earth.

A fun fact is that Kardashev himself actually wanted humanity in 1964 to be understood as a type 1 civilization already. Look it up in his original paper. I suppose Sagan’s and Kaku’s interpretation of the scale prevailed and thus this kind of measure is not applied here.

Anyway, a type 2 civilization is able to harness all the energy emitted by its parent-star in all directions. For the sun that would be roughly 1026 Watts. A type 3 civilization would be so god-like that it can make use of all the energy in its galaxy. In terms of the milky way that is about 1036 Watts.

Now, what Sagan did was taking the entire global energy consumption and ­­plug it into his invented interpolation equation:

Where K is the score on the Kardashev Scale and P is the energy capability (measured in Watts) of the civilization adjusted by the factors you see such as taking its logarithm. It is really just an interpolation of the values for type 1,2 and 3 mentioned above. Anyhow that is when you plug in the energy consumption of humanity today (2017) you roughly get 0.725 (based on International Energy Agency (IEA) data).

Here I want to argue that this does not make a lot of sense considering Kardashev’s original intention. Sagan’s equation is perfectly fine, but the value plugged in is not the appropriate one.

Sagan suggested to use the total world energy consumption (WEC) in his interpolation equation. Total WEC, however, includes the use of fossil fuels which is not in line with the concept. Fossil fuels are not a mean of harnessing the sun’s energy directly. Fossil fuels only can be harnessed after the millions of years they require to form. It requires a totally different kind of technology to dig for oil than building a photo-voltaic system. Moreover, fossil fuels are depletable in the foreseeable future and not a reliant mean to power our civilization in the long-term. Consequently, they should be considered to be transitional technologies from a state of pre-industrial conditions to modern ones but not be included in the means of an advanced civilization. Contrarily, renewable energy sources like solar power, wind power, hydro and biomass draw directly from the radiation of the sun. Even wind is just solar energy stored in the atmosphere, and biomass is literally radiation energy transformed into carbon-based life. Here I do not take nuclear energy and potential future energies like nuclear fusion into account. But fusion obviously is not a commercial source of energy yet and traditional nuclear reactors are not directly drawing from the sun either and are a very controversial form of energy due their waste products.

If you take the amount of energy provided only by renewable energies including:

  • All kinds of solar power
  • Wind
  • Hydro
  • Biomass
  • Geo-thermal

you arrive at a score of 0.64. According to the IEA, Key World Energy Statistics 2017 these renewable sources contributed roughly 13.5% to overall energy supply in 2017. This supply-based measure is also more appropriate than a consumption-based one because it actually refers to an amount of energy generated, before it is distributed in society. Therefore, a supply-based measure is closer to Kardashev’s concept of “capability to generate energy through technology” than a consumption-based measure.

You might ask then “When do we finally become a type-1 civilization?”. Physicist, Michio Kaku has repeatedly claimed that we attain type-1 status in 100 years for example here: ( Although, I admire Kaku, his books and his work, in my opinion that is a rather ungrounded statement since Kaku just assumes that technology will evolve so spectacularly in the 21st century that we can control any form of energy on earth and quote: “play with it”. Kaku even argues we would be able to harness the energy of volcanoes and earth quakes. I do not see any significant advances in that direction, but I am always willing to be corrected if somebody provides me evidence. I do think, more realistically, and based on the argument presented here, you could for example extrapolate recent historic growth rates of renewable energy capacity into the future. This way, we can see how long it takes to go from current renewable energy supply to the one which represents a type-1 civilization. Figure 1 below shows that time-line. And yes, it would almost take 500 years and not just 100. Very precisely around the year 2500 humanity would attain type-1 status. Holding these growth rates constant, you can see how in the first 300 years from now on the energy supplied by renewable energy grows rather slowly and only in the 24th century starts to level up due to the nature of exponential growth. Of course, these assumptions underlie various limitations too. For example we cannot wait 300 years to replace all fossil fuels by renewables ones, simply because all fossil fuels are likely to run out within the next 150 years. Oil even considerably earlier. Constant growth rates may not be very accurate either since they can vary over time. They may be a little faster in the beginning and level off later instead of ending in exponential growth. It provides a more humble, realistic and yet visionary picture of what is going to happen but it is not supposed to demotivate. Quite the opposite, I feel like this should motivate us to accelerate building up renewable energy capacities if we want to have the future of an advanced civilization…