Light to life: Photochemical processes drove the cycling of bio-essential nutrients on the early Earth

<p indent="0mm">The Archean Eon witnessed the initiation of the co-evolution of geosphere and biosphere, which was potentially linked by the geochemical cycles of nutrient elements. However, the distinctive environmental conditions should have resulted in vastly different geochemical cycles of the nutrients and thus their availability on the early Earth. Here, we overview the current understanding of Archean geochemical cycles and availability of nutrients, especially those thought to limit the origin and productivity of early life. Particularly, we emphasize some recent advances on the large impacts of photochemistry in early nutrients′ cycles and assess the potentially important roles of photogeochemistry in the co-evolution of environment and biology on the early Earth. At the end, we advocate for more attention to the role of photochemistry in planetary habitability, including the early Earth, Mars, and other planetary bodies.