What Alien Civilizations We've Never Met Can Teach Us About Saving the Earth
New findings about the astrobiology in the cosmos may hold key insights to building a sustainable civilization here on Earth.
The closest intelligent life may be thousands of light-years away, but aliens may still be able to help us solve some of humanity's greatest challenges. For instance, how to transition to sustainable, low-carbon economies before our biosphere falls to pieces.
Astronomers Adam Frank and Woodruff Sullivan believe that, when it comes to 21st century crises—global warming,ocean acidification,the sixth mass extinction—there's solace to be found in the cosmos. See, all of this has (probably) happened before. That is, we're probably not the first intelligent species to find ourselves at a crossroads between sustainability and self-annihilation.
Now, this may sound like science-fictional speculation. But it's actually a conclusion arrived at by math, and it may herald a new way of thinking about conservation. In Frank and Sullivan's new paper, published in the journal Anthropocene, the researchers call for the creation of a new research program that merges the space-oriented field of astrobiology and the Earth-oriented field of sustainability. While sustainability science focuses on the effects of a single species (us) during a particular epoch, astrobiology broadens its purview to all possible species, everywhere. But the two fields share common goals:
"Sustainability science and astrobiology both seek to understand the intimate, symbiotic, and continually evolving connections between life and host planets," Frank and Sullivan write. Furthermore, emerging theories in astrobiology may help us develop a better understanding of the different pathways a "species with energy intensive technology," or SWEIT, can follow.
To demonstrate how, the researchers turn to the Drake equation, which pulls together astronomical, biological and sociological factors to estimate the probable number of radio-transmitting civilizations in the galaxy. In their paper, the authors focus on one of Drake's completely mysterious sociological factors: L, the average lifetime of a SWEIT. This single factor, the authors argue, ties together astrobiology and sustainability. Can we expect a technological civilization to last 200 years? A thousand years? A million?
If technological civilization had happened on Earth two billion years ago, we could have burned every chunk of coal on the planet and been fine
At present, there's clearly no way of pinning an exact number to L. But we can start amassing relevant factors.
Just this past week, scientists plugged new data from the Kepler mission into the Drake equation and demonstrated there may be millions to billions of life-harboring worlds in the Milky Way. Frank and Sullivan calculate that, even if the chances of finding intelligent life on other worlds are one in a trillion, there should still be roughly 1,000 planets in our corner of the universe that have harbored a technologically advanced civilization.
"We did this calculation to show that it's not unreasonable for other technological civilizations to have emerged in our local universe," Frank told me in an interview. "Given a thousand technological civilizations, it's reasonable to start asking what their average properties are."
Using dynamical systems theory, the authors show how the trajectory of a hypothetical SWEIT can be mapped in a multidimensional space. Axes of this space may include energy consumption rates, the position of a planet in its star's habitable zone, population size and planetary feedbacks, both from natural causes and the SWEIT itself.
This approach may help us put our current sustainability dilemma in a broader context. For instance, present-day Earth lies at theinner edge of our sun's habitable zone, making it particularly susceptible to greenhouse forcing.
"If technological civilization had happened on Earth two billion years ago, we could have burned every chunk of coal on the planet and been fine," said Frank. "That's an actual astrobiological insight that matters for sustainability."
By modeling the different techno-evolutionary paths a SWEIT might take, Frank hopes we can start charting some alternate paths.
"I imagine bundles of trajectories, some splitting off and collapsing, some settling into a sustainable limit cycle," Frank told me. "After you model these different trajectories, you could look back and ask: What separated those scenarios? And if a species is headed toward collapse, how fast does that species have to make a change to get on another path?"
So, astrobiological perspectives can give us a new way of understanding whether, and how, a species can avoid self-annihilation. Insights from a range of astrobiology topics—climate change, mass extinctions and planetary habitability—may help us hone in on the specific ingredients needed for a sustainable future. The approach doesn't offer any solutions yet, but rather, a framework for understanding the spectrum of possibilities.
At the very least, astrobiology promises to inject a healthy dose of humility into the climate debate.
"One point is clear, both astrobiology and sustainability science tell us that the Earth will be fine in the long run," Frank and Sullivan write. "The prospects are, however, less clear for Homo sapiens."