What kept early Earth warm? Examining a diverse range of greenhouse gases

Over Earth's history the solar constant has increased from 70% of its current value. Over much of this period evidence has been found for a temperate climate and lack of glaciation. Enhancements in a variety of different greenhouse gases, most of which are biogenic, have been suggested to have kept the early Earth warm. However, different modelling approaches (and some model errors) have hampered comparison of different proposals. Here we present initial results of a project to calculate high-accuracy radiative forcings for all proposed greenhouse gases for early Earth (and some that have not previously been proposed). By reducing uncertainties in the radiative transfer calculations, we hope to push forward the debate on what kept early Earth warm, allowing future work to focus more on what biogeochemical processes controlled atmospheric composition.