The existence of advanced alien civilizations has long been a topic of debate in the scientific community. Researchers from the Austrian Academy of Sciences have shown that the conditions necessary for the emergence of intelligent life may be much rarer than we think. This study was presented at the Europlanet Science Congress held in Helsinki and conducted by Manuel Scherf and Helmut Lammer.
With a risk-reducing and forward-looking perspective, it was concluded that the existence of plate tectonics plays a critical role in maintaining the biosphere. This geological process, which regulates the amount of carbon dioxide in the atmosphere, helps keep the planet’s temperature balanced. If CO2 levels are low, photosynthesis becomes difficult; if too high, the greenhouse effect makes the planet uninhabitable. However, plate tectonics alone do not seem sufficient. Over time, excessive reduction of CO2 in the atmosphere can halt photosynthesis. Therefore, a longer biosphere lifespan than the process required for the emergence of intelligent life plays a key role. On Earth, this process lasts approximately 4.5 billion years.
The importance of oxygen for technology Research emphasizes that the composition of the atmosphere is also decisive in the emergence of technological civilizations. Not only for sustaining life, but also for maintaining a certain atmospheric structure, oxygen is critical. It is noted that when the oxygen level in the atmosphere drops below 18%, the sustainability of an open flame becomes difficult; this can hinder metalworking, cooking, and other technological steps.
Modeling studies aim to understand how long biospheres can withstand under different planetary and atmospheric conditions and whether this duration is sufficient for the evolution of technological civilizations. The results indicate that the likelihood of having a wise civilization similar to Earth in the Milky Way is quite low. If such a civilization exists, it is suggested that its closest counterpart could be about 33,000 light-years away. Additionally, for this civilization to be simultaneous with humanity, it would need to survive at least 280,000 years, perhaps longer. In other words, providing suitable planetary conditions is not enough; these conditions must remain stable for billions of years. Such a challenge considerably reduces the probability of intelligent life in the universe.
Continuing the search still makes sense Researchers believe that the search for extraterrestrial intelligence (SETI) should be continued. Scherf states, “Intelligent life forms may be rare in the universe, but we need to look for them to obtain definitive proof.” Even if the results are inconclusive, this theoretical framework will be strengthened; if a clue is found, it could be a scientific revolution in human history.
