Abstract:
The habitability of the Earth for humans has changed dramatically over time, and we would generally not want to live on the ancient Earth. But why did this happen? Will it continue to change? and should a similar timeline for habitability define other rocky planets with similar biospheres? To explore these questions my research group has built what we call an 'Earth Evolution Model' - a 3D Earth System Model that can be integrated over billions of years to explore dynamic changes in global biogeochemical cycles over these timeframes. We think we now have some useful conclusions on why oxygen concentrations have risen over time and why planetary temperature has oscillated around a generally warm greenhouse state, and can begin to make predictions about what may be in store for our world in the next millions and billions of years, and how we might expect human-habitable conditions to arise elsewhere.