The collective activity of life – all microbes, plants and animals – has changed planet Earth.
Take, for example, plants: plants “invented” a way to undergo photosynthesis to enhance their own survival, but in doing so they released oxygen that changed the entire function of our planet. This is just one example of individual life forms performing their own tasks, but collectively having an impact on a planetary scale.
If the collective activity of life – known as the biosphere – can change the world, could the collective activity of cognition and action based on that cognition also change a planet? Once the biosphere evolved, the Earth took on a life of its own. If a living planet has its own life, can it also have its own mind?
These are questions posed by Adam Frank, Helen F. and Fred H. Gowen Professor of Physics and Astronomy at the University of Rochester, and his colleagues David Grinspoon at the Planetary Science Institute and Sara Walker at Arizona State University, in an article published in the International Journal of Astrobiology. Their self-proclaimed “thought experiment” combines current scientific understanding of Earth with broader questions about how life changes a planet. In the paper, the researchers discuss what they call “planetary intelligence” – the idea of cognitive activity operating on a planetary scale – to spark new ideas about how humans might tackling global issues such as climate change.
As Frank says, “If we ever hope to survive as a species, we must use our intelligence for the greater good of the planet.”
An “immature technosphere”
Frank, Grinspoon and Walker draw on ideas such as the Gaia hypothesis – which proposes that the biosphere interacts strongly with the non-living geologic systems of air, water and earth to maintain the habitable state of Earth – to explain that even a non-technologically capable species can display Planetary Intelligence. The key is that the collective activity of life creates a self-sustaining system.
For example, says Frank, many recent studies have shown how the roots of trees in a forest connect via underground networks of fungi called mycorrhizal networks. If one part of the forest needs nutrients, the other parts send the stressed parts the nutrients they need to survive, via the mycorrhizal network. In this way, the forest maintains its own viability.
Right now, our civilization is what researchers call an “immature technosphere,” a conglomeration of human-generated systems and technologies that directly affect the planet but are not self-sustaining. For example, the majority of our energy consumption involves burning fossil fuels that degrade the Earth’s oceans and atmosphere. The technology and energy we consume to survive destroys our home planet, which, in turn, will destroy our species.
To survive as a species, therefore, we must work collectively in the best interests of the planet.
But, says Frank, “we don’t yet have the ability to respond collectively in the best interest of the planet. There is intelligence on Earth, but there is no planetary intelligence.”
Towards a mature technosphere
The researchers posit four stages of Earth’s past and possible future to illustrate how planetary intelligence could play a role in humanity’s long-term future. They also show how these stages of evolution driven by planetary intelligence can be a feature of any planet in the galaxy that evolves life and a sustainable technological civilization.
- Stage 1 — Immature Biosphere: characteristic of very ancient Earth, billions of years ago and before a technological species, when microbes were present but vegetation had not yet appeared. There were few global feedbacks because life could not exert forces on Earth’s atmosphere, hydrosphere, and other planetary systems.
- Stage 2 — Mature biosphere: characteristic of Earth, also before a technological species, from about 2.5 billion to 540 million years ago. Stable continents formed, vegetation and photosynthesis developed, oxygen accumulated in the atmosphere, and the ozone layer emerged. The biosphere has exerted a strong influence on the Earth, perhaps helping to maintain Earth’s habitability.
- Stage 3 — Immature Technosphere: characteristic of present-day Earth, with interconnected systems of communication, transportation, technology, electricity and computers. The technosphere, however, is still immature, as it is not integrated with other Earth systems, such as the atmosphere. Instead, it draws matter and energy from Earth systems in a way that will drive the whole into a new state that likely won’t include the technosphere itself. Our current technosphere works, in the long run, against itself.
- Stage 4 — Mature Technosphere: where Earth should aim to be in the future, Frank says, with technology systems in place that benefit the entire planet, including global harvesting of energy in forms like solar that don’t harm the biosphere. The mature technosphere is one that has co-evolved with the biosphere into a form that allows both the technosphere and the biosphere to thrive.
“Planets evolve through immature and mature stages, and planetary intelligence indicates when you get to a mature planet,” Frank explains. “The million dollar question is what does planetary intelligence look like and what does it mean for us in practice, as we don’t yet know how to move into a mature technosphere.”
The Complex System of Planetary Intelligence
Although we don’t yet know precisely how planetary intelligence might manifest, the researchers note that a mature technosphere involves the integration of technological systems with Earth through a network of feedback loops that make up a complex system.
Simply put, a complex system is anything that is built from smaller parts that interact in such a way that the overall behavior of the system depends entirely on the interaction. In other words, the sum is more than the whole of its parts. Examples of complex systems include forests, the internet, financial markets, and the human brain.
By its very nature, a complex system has entirely new properties that emerge when individual parts interact. It is difficult to discern the personality of a human being, for example, only by examining the neurons of his brain.
This means that it is difficult to predict exactly what properties might emerge when individuals form a planetary intelligence. However, a complex system like the planetary intelligence will have, according to the researchers, two determining characteristics: it will have an emergent behavior and will have to be self-sustaining.
“The biosphere figured out how to support life on its own billions of years ago by creating systems to move nitrogen and transport carbon,” Frank says. “Now we have to figure out how to have the same kind of self-sustaining characteristics with the technosphere.”
The search for extraterrestrial life
Despite some efforts, including a global ban on some environmentally harmful chemicals and a trend to use more solar power, “we don’t yet have a planetary intelligence or a mature technosphere,” he says. “But the point of this research is to show where we should be heading.”
Raising these questions, Frank says, will not only provide information about the past, present and future survival of life on Earth, but will also aid in the search for life and civilizations outside our solar system. Frank, for example, is the principal investigator of a NASA grant to search for technosignatures of civilizations on planets orbiting distant stars.
“We say that the only technological civilizations we could ever see – the ones we should expect see – are those who have not committed suicide, which means they must have reached the stage of true planetary intelligence,” he says. “That’s the power of this line of inquiry: it unites this we need to know to survive the climate crisis along with what could happen on any planet where life and intelligence evolve.”