Escaping the Great Filter: The Future of Civilization and the Search for Technosignatures

Abstract Human civilization continues to experience rapid growth in energy consumption, while projections of population stabilization remain uncertain. A continued trajectory of exponential energy use would cause direct heating of the planet by ∼2300, which would also coincide with a transition to a Kardashev type-I civilization. If such patterns of energy consumption are typical for other technological civilizations, then the lack of evidence for extraterrestrial life suggests that Earth may be among the first. This implies that a “Great Filter” may exist in the near future, which would mark a critical juncture of whether civilization on Earth becomes spacefaring or extinct. Any extant technological civilizations are likely those that have achieved long-term equilibrium with energy consumption and population growth. The search for technosignatures by ongoing ground- and space-based observatories will provide a way to test the Great Filter hypothesis and examine the extent to which energy-intensive civilizations occur in the galaxy.