Introduction: This article is translated from the Universe Today article "When Will Humanity Become a Type I Civilization?" by BRIAN KOBERLEIN. April 18, 2022. The content of the article does not represent the views of the translator.
In measuring the progress of human civilization, we have various indicators, such as population growth, the rise and fall of empires, and technological capabilities for space travel, among others.
One simple indicator is to calculate the total amount of energy that a human civilization can use during a specific period. With the expansion of human territory and technological development, energy harvesting has become one of our most useful technologies.
If we assume that civilizations on other planets may also have similar technologies, the energy consumption level of a civilization can serve as good evidence of its technological strength. This is the idea behind the Kardashev scale.
This scale was proposed by Soviet astrophysicist Nikolai Kardashev in 1964. Based on this scale, he divided civilizations into three types: planetary civilizations, stellar civilizations, and galactic civilizations.
A Type I civilization has the ability to harness energy equivalent to the total energy radiated by its parent star. A Type II civilization can harness energy on the scale of the energy radiated by the stars in its solar system. A Type III civilization can harness the energy of its entire galaxy.
This idea, popularized by Carl Sagan, also introduced the concept of measuring the energy consumption of civilizations on a continuous scale, rather than simply dividing them into three types.
So, what type of civilization are we humans now? Although humans can already use a tremendous amount of energy, we are not yet qualified to be a Type I civilization.
The average power radiated by the Sun to the Earth is about 10^16 watts, while the power consumption of human civilization is currently around 10^13 watts. According to Carl Sagan's smooth scale, we are roughly a Type 0.73 civilization.
For life forms that have evolved from apes like us, this is still a decent achievement. But an interesting question arises: Can we develop into a Type I civilization? After all, if we were to collect all the solar energy reaching the Earth, the Earth would no longer be suitable for biological life.
Illustration of Kardashev Type III civilization (Wikipedia, cc-by-sa 3.0)
Recently, a paper titled "Avoiding the Great Filter: Predicting the Timeline for Humanity to Reach Kardashev Type I Civilization" was published on arXiv, which explored this issue. The paper investigated three major energy sources (fossil fuels, nuclear energy, and renewable energy) and calculated their potential growth trends.
On one hand, reaching the Type I civilization stage seems relatively easy. As long as energy production is set as the primary goal of human civilization, we will eventually achieve it. However, the energy sources used by humans each have their limitations.
In extreme cases, such as burning all our fossil fuels, the resulting climate change would bring catastrophic consequences to the biosphere, leading to the so-called Great Filter event. If humanity becomes extinct, it would be impossible to become a Type I civilization.
Therefore, the team adopted a more sophisticated approach, analyzing the physical limitations of each energy type and considering the balance between using these energy sources and the levels of climate change and pollution, with reference to the United Nations Framework Convention on Climate Change and the International Energy Agency.
They found that even considering the limitations of realistic indicators, it is still possible for humanity to develop into a Type I civilization. However, it is unlikely that we will reach this level before the year 2371.
This is not necessarily a bad thing. After all, the Kardashev scale is just a cold indicator.
Although technologically advanced civilizations require a large amount of energy, we have also seen that low-power computing and energy efficiency improvements can allow us to continue developing technology without increasing or decreasing energy consumption.
While this study suggests that it is possible for us to develop into a Type I civilization, it is also possible that we will develop advanced enough to discover that we don't actually need to become a Type I civilization.