A sluggish mid-Proterozoic biosphere and its effect on Earth's redox balance

The possibility of low but nontrivial atmospheric oxygen (O2) levels during the mid-Proterozoic (between 1.8 and 0.8 billion years ago, Ga) has important ramifications for understanding Earth's O2 cycle, the evolution of complex life and evolving climate stability. However, the regulatory mechanisms and redox fluxes required to stabilize these O2... Show more