What We Talk About When We Talk About Earth's Oxygenation
When: October 31, 2016 1PM PDT
As the possibility of detecting the atmospheric composition of terrestrial exoplanets moves from the realm of science fiction to science we have become increasingly focused on determining what Earth would look like if analyzed remotely over its long history. Beyond just providing a record of Earth’s atmospheric composition, our goal is to determine how biological evolution has shaped surface oxygenation. A better understanding of our own planet’s atmospheric evolution will improve the framework we use to interpret exoplanetary atmospheres. To unravel the tale of Earth’s oxygenation and biological evolution, many key questions need to be answered. In this talk I will focus on providing a new view of atmospheric oxygen levels through Earth’s middle history, where traditional constraints on redox sensitive atmospheric components are so imprecise it is difficult to estimate Earth’s ‘detectability’. Further, I will provide new constraints on the factors leading to the climatic and biogeochemical turbulence that characterized the transition to the more modern (Phanerozoic) Earth.