Is Insolation the Dominant Factor in Triggering a Runaway Greenhouse?

Establish whether stellar insolation is the dominant control on the onset of a runaway greenhouse state on terrestrial planets, as opposed to other influences such as atmospheric composition, planetary mass, rotation, and cloud feedbacks.

Background

Habitable Zone and Venus Zone boundaries are model-dependent, and planetary climate is influenced by multiple factors beyond insolation. Understanding which factors dominate the transition to a runaway greenhouse is critical for interpreting exoplanet observations and for applying Solar System insights to other systems.

Determining the primacy of insolation in initiating a runaway greenhouse will refine occurrence estimates of Venus-like worlds and inform target selection and interpretation for atmospheric characterization.

References

Furthermore, as noted above, the insolation flux of a planet is one in a plethora of factors that influence planetary climate and has not (yet, at least) been clearly established as the dominant factor in determining whether a planet enters a runaway greenhouse state early in its evolution.

— Venus as an Anchor Point for Planetary Habitability (2403.08830 - Kane et al., 12 Mar 2024) in Section 5.2. Exo Venus Candidates