Climate change threatens life on Earth. It may have also killed alien civilizations in energy-intense worlds.
Adam Frank, an astrophysicist from the University of Rochester in New York, and colleagues studied how alien civilizations may rise and fall if their planet's limited natural resources are increasingly converted into energy.
The study aims to get a 10,000-light-year view of man-made climate change and show how a technologically advanced population and its planet may develop together.
Easter Island Inhabitants
The researchers used a mathematical model based on the disappearance of a lost civilization on Earth, the former inhabitants of the Easter Island.
This people started to colonize the island between 400 and 700 AD and reached the peak of their population believed to be about 10,000 around 12,000 to 1500 AD. The inhabitants, however, depleted their resources by the 18th century and their population dropped to just about 2,000.
Frank explained that the die-off has something to do with a concept known as carrying capacity, the maximum number of species that an environment can support. Many studies suggest that the depletion of resources at Easter Island led to the starvation of its inhabitants and terminated the civilization.
Frank said that planet Earth's response to civilization building is what climate change is all about.
"The laws of physics demand that any young population, building an energy-intensive civilization like ours, is going to have feedback on its planet," he said.
The researcher cited the importance of studying the impact of climate change from an astrobiological perspective. Climate change in a cosmic context may provide better insights on what happens to Earth and how humans have to address it.
Potential Scenarios For Energy-Intense Civilizations
Using a mathematical model, Frank and colleagues found four potential scenarios that may occur for energy-intense civilizations.
By thinking planets and civilizations, including alien ones, as a whole, the researchers argued that they can better predict what needs to be done for human civilization to survive.
Three of the four trajectories ended in an apocalypse. The remaining one, which involved a path that converted the whole society to sustainable energy sources worked, but this happened only when civilizations acknowledged the damage they did to their planet and responded in the right way.
Frank said that this scenario is also the most frightening because regardless that people did the right thing, their population could still collapse if they wait too long.
The researchers published their findings in the journal Astrobiology on May 1.