Artist concept of an alien planet. Could this be out there waiting for us to explore?

Artist concept of an alien planet. Could this be out there waiting for us to explore? (Image credit: Mark Garlick/Science Photo Library via Getty Images)

Our species is facing a crucial moment in human history. Either we develop the technology to safely harness the energy needed to escape our planet, or we kill ourselves in some great cataclysm, according to a new study.

The new paper argues that if we can achieve the former and avoid the latter, we might become a truly interplanetary species in as little as 200 years.

Jonathan Jiang, lead author of the study, told Live Science that the Earth is a tiny dot surrounded by darkness.

To leave our planet for good, we need to dramatically increase the use of nuclear and renewable energy, as well as safeguard those energy sources from being used for malicious purposes.


The next few decades will be critical if humanity can safely transition away from fossil fuels.

Illustration of TRAPPIST-1 Planets as of Feb. 2018.

Illustration of TRAPPIST-1 Planets as of Feb. 2018. (Image credit: NASA/JPL-Caltech)

The measurement scheme proposed by Kardashev in 1964 was later modified by Carl Sagan. It all comes down to how much energy a species can use for its own purposes, whether that's exploring the universe or playing video games.

9 strange, scientific excuses for why scientists haven't found aliens yet.

A Kardashev type I civilization can use all the energy available on the home planet, including all the sources of energy in the ground, and all the energy falling onto that planet. This is around 1016 watt for Earth.

A type II civilization can exploit the entire energy output of a single star, because they consume 10 times the amount of energy. Most of the energy in an entire galaxy can be used by type III species.

The human species is well below the type I threshold, but our energy consumption grows every year. More people are using more power per capita, but that power comes at a cost: namely, the threat to our biosphere from the release of carbon and pollutants, and the risk posed by the ability to use powerful means of energy storage and delivery for destructive purposes.

The great filter

Artist concept of the surface of exoplanet TRAPPIST-1f.

Artist concept of the surface of exoplanet TRAPPIST-1f. (Image credit: NASA/JPL-Caltech/T. Pyle (IPAC))

Scientists have found no evidence of advanced alien civilizations because of the danger posed by the increased consumption of energy. If the development of life and intelligence is not unique to Earth, then the universe should be filled with intelligent creatures. The Milky Way is billions of years old, even though we haven't been around for very long. Somewhere should have reached the Type III stage and begun exploring the universe.

By the time humans became intelligent, there should have been someone there to meet us or at least leave a gift.

We are alone as far as we can tell. It appears that life and intelligent life are very rare. Some processes may remove intelligent life from the scene before a civilization can reach higher stages of development. Most of these filters are different forms of self-destruction.

We haven't even cracked the first rung of the Kardashev scale, and we are already capable of self-destruction as a species. A few countries have the ability to wipe out all humans on the planet.

Jiang said that they are their own Great Filter.

The trick is to avoid self-destruction while we ramp up our energy use to the point where we can reliably exist on multiple worlds at once, even if it is just in the solar system. Having a human presence on more than one planet is a strong bulwark against self-destruction. To achieve multi-planetary status requires an enormous amount of energy, not just for establishing short-term colonies, but also for maintaining self-sufficient cities.

The knife's edge

Jiang and his team explored the best way to reach Type I status in a paper uploaded in April to the journal arXiv. The researchers followed the recommendations of the United Nations Framework Convention on Climate Change, which showed consequences for the continued use of fossil fuels. If we don't switch to nuclear and renewable energy quickly, we will do too much damage to our biosphere to keep climbing the Kardashev scale.

The study assumed 2.5% growth in the use of renewable and nuclear energy each year, and found that in the next 20 to 30 years, those forms of energy use will displace fossil fuels. Nuclear and renewable energy sources have the ability to keep growing in output without putting strain on the biosphere, and if we continue at our current rate of consumption we will reachType I status in the year 2361, the team found.

The uncertainty on the estimate was probably around 100 years, Jiang acknowledges that the calculations included a lot of assumptions. The calculations had to assume that we would find safe ways to handle nuclear waste and that the increased ability to harness energy wouldn't lead to disaster. If we can maintain this course, we can set the stage for our species to be protected for generations to come.

The original was published on Live Science.