UW News

November 19, 2014

What are our survival chances? Astrobiology meets sustainability science

UW News

The Earth as seen by the crew of Apollo 4 from about 10 miles up. University of Washington astronomer Woody Sullivan and co-author ask, have there been other species with energy-intensive technology? And if so, how long did they last?

The Earth, seen from the unmanned Apollo 4 at an altitude of about 9,544 nautical miles miles. U. of Washington astronomer Woody Sullivan and co-author ask, have there been other species with energy-intensive technology? And if so, how long did they last?NASA

We Homo sapiens and our energy-gobbling technologies are changing the very ecology of the Earth. But even as these human-caused changes unfold, some wonder whether we have doomed ourselves to extinction.

In a new paper in the journal Anthropocene, University of Washington astronomer Woodruff Sullivan and co-author Adam Frank, a University of Rochester astrophysicist and a UW alumnus, suggest this might not be the first time “where the primary agent of causation is knowingly watching it all happen and pondering options for its own future.”

The authors revisit the famous 1961 Drake Equation, created to estimate the number of intelligent civilizations in the universe. Focusing on the average lifetime of a “species with energy-intensive technology,” they conclude: “Even with the odds of evolving (such a civilization) on a given habitable planet being one in one million billion, within our local region of the cosmos at least 1,000 species will still have passed through the transition humanity faces today.”

That got them considering what the average lifetime of such a species might be.

“Is it 200 years, 500 years or 50,000 years? Answering this question is at the root of all our concerns about the sustainability of human society,” said Frank. “Are we the first and only technologically-intensive civilization in the entire history of the universe? If not, shouldn’t we stand to learn something from the past successes and failures of these other species?”

The authors also recommend that those studying earthly sustainability science might learn a lot from the starry field of astrobiology, which takes a long view of the evolution of life and planets. They suggest a research program to better understand the paths a biosphere might follow once a species with energy-intensive technology emerges.”

Such an astrobiological perspective, they write, “allows the opportunities and crises occurring along the trajectory of human culture to be seen more broadly as, perhaps, critical junctures facing any species whose activity reaches significant level of feedback on its host planet (whether Earth or another planet).”

In other words, they suggest, sustainability might be a phase all, or at least many, technological species must experience.

“The point is to see that our current situation may, in some sense, be natural or at least a natural and generic consequence of certain evolutionary pathways.”

Sullivan said, “By broadening the issue to think about other possible planets with other possible technical civilizations, we can perhaps gain some insights into our own situation.”

On one thing, however, astrobiology and sustainability science already agree, Frank and Sullivan conclude: “Earth will be fine in the long run. The prospects are, however, less clear for Homo sapiens.”