As oxygen is essential for respiration and metabolism for multicellular organisms on Earth, its presence may be crucial for the development of a complex biosphere on other planets. And because life itself, through photosynthesis, contributed to creating our oxygen-rich atmosphere, oxygen has long been considered as a possible biosignature. Here we consider the relationship between atmospheric oxygen and the development of technology. We argue that only planets with substantial oxygen partial pressure (\(p_{{\mathrm{O}}_2}\)) will be capable of developing advanced technospheres and hence technosignatures that we can detect. But open-air combustion (needed, for example, for metallurgy), is possible only in Earth-like atmospheres when \(p_{{\mathrm{O}}_2}\) ≥ 18%. This limit is higher than the one needed to sustain a complex biosphere and multicellular organisms. We further review other possible planetary atmospheric compositions and conclude that oxygen is the most likely candidate for the evolution of technological species. Thus, the presence of \(p_{{\mathrm{O}}_2}\) ≥ 18% in exoplanet atmospheres may represent a contextual prior required for the planning and interpretation of technosignature searches.

由于氧气对于地球上多细胞生物的呼吸和新陈代谢至关重要，因此它的存在对于其他行星上复杂生物圈的发展可能至关重要。由于生命本身通过光合作用创造了富氧大气，因此氧气长期以来被认为是一种可能的生物特征。这里我们考虑一下大气中的氧气与技术发展之间的关系。我们认为，只有具有大量氧分压（\(p_{{\mathrm{O}}_2}\)）的行星才能够发展先进的技术圈，从而发展出我们可以检测到的技术特征。但是露天燃烧（例如冶金所需）只有在类地大气中当\(p_{{\mathrm{O}}_2}\)  ≥ 18% 时才可能实现。这一限制高于维持复杂生物圈和多细胞生物体所需的限制。我们进一步审查了其他可能的行星大气成分，并得出结论，氧气是技术物种进化的最有可能的候选者。因此，系外行星大气中\(p_{{\mathrm{O}}_2}\) ≥ 18%的存在 可能代表了技术特征搜索的规划和解释所需的上下文先验。