The School of Earth and Atmospheric Sciences Presents Dr. Chris Reinhard, GA Tech

Earth’s History as a Natural Lab for Planetary Science

The human species has emerged after ~4.5 billion years of planetary evolution as a relative newcomer on a largely microbial world. From this vantage, advances in analytical geochemistry and quantitative modeling have reshaped our understanding of the texture of Earth’s evolution as a habitable planet, and our ability to predict the long-term future of Earth and its biosphere. At the same time, telescope observations have revealed an astonishing number and diversity of planets beyond our solar system, some of which may harbor their own biospheres. 

These pursuits share deep roots in their drive to understand the stellar, biological, and planetary factors controlling habitability, atmospheric composition, and climate evolution on living worlds.

This talk will provide one example of our effort to combine better empirical constraints on Earth’s atmospheric composition with large-scale Earth system models, with the dual aims of tracking major shifts in the chemistry of Earth’s ocean-atmosphere system and informing the search for life beyond our solar system. In particular, it will evaluate the temporal evolution of Earth’s most well-known remotely detectable biosignature — the simultaneous presence of significant atmospheric abundances of oxygen and methane — and will discuss the potential insights into remote observation strategies of exoplanets that emerge from a fuller understanding of how this signal has changed with time.