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Earth is unique among the terrestrial planets in our Solar System in having a fluid envelope that fosters life. The secrets behind Earth’s habitable surface conditions are well-tuned cycles of carbon (C) and other life-essential volatiles. While on time-scales of ten to thousands of years the chemistry of fluids in the atmosphere, hydrosphere, and biosphere is dictated by fluxes of carbon between near surface reservoirs (short-term carbon cycle), over hundreds of millions to billions of years it is maintained by fluxes of carbon between the Earth’s interior, more specifically the mantle, and the surficial reservoirs (long-term carbon cycle). Subduction zones, where oceanic lithosphere plunges back into the mantle, are critical settings where the long-term carbon fluxes between the surface reservoirs and the Earth’s mantle are modulated. In this talk, I will review some of ways the scientific community have thought about the topic of Earth’s long-term carbon cycle. In particular, can we say anything about how such carbon cycle may have evolved with geologic time? Also, is there any plausible link between Earth’s deep carbon cycle and Earth’s oxygen-rich atmosphere? |