A recent study by astrophysicists suggests that advanced alien civilisations might only have a thousand years before their planets become uninhabitable due to climate change. This alarming finding stems from simulations exploring the trajectory of technological growth and energy consumption of these hypothetical societies. Even those relying on renewable energy could face dire consequences, as any increase in energy production inevitably leads to heat generation that the planet cannot support. This research has been shared on the preprint server arXiv and is currently awaiting peer review.
Comparisons to Human Energy Consumption
The study's lead authors, Manasvi Lingam, an astrophysicist at Florida Tech, and Amedeo Balbi, an associate professor of astronomy and astrophysics at Tor Vergata University of Rome, are drawing parallels between human energy consumption and the potential fate of extraterrestrial societies. Since the 1800s, human energy use has surged dramatically, with 2023 estimates indicating approximately 180,000 terawatt hours (TWh) consumed. This level of energy consumption, primarily from fossil fuels, has escalated global temperatures at an unsustainable rate. Even a shift to renewable sources would not halt this growth and would still result in increased energy demands.
The Role of Thermodynamics in Planetary Health
The second law of thermodynamics plays a crucial role in understanding this phenomenon. It posits that no energy system is perfect, meaning some energy is always lost in the form of heat. Lingam uses the analogy of a leaky bathtub to illustrate how, as a society grows, even a small leak can lead to catastrophic outcomes when the bathtub becomes overfilled.
Challenges for Astrobiology and the Search for Life
The implications of this study extend beyond the survival of alien life; they also pose significant challenges for astrobiologists in their quest to find intelligent life beyond Earth. With such a short window for survival, the study indicates that many potential civilisations may self-destruct long before they could be detected.
A Sustainable Path Forward for Civilisations
Lingam emphasises that there is an alternative. Civilisations could opt for a balanced growth approach, allowing them to coexist sustainably with their environments, potentially enabling survival for millennia.
