2007/11/30 by David S. Spiegel, Kristen Menou, Caleb Scharf +1 · 2 citations
Physics and Astronomy · #Albedo (alchemy) #Astro and Planetary Science #Astrobiology #Astronomy #Circumstellar habitable zone #Climatology #Environmental science #Exoplanet #Geology #Habitability #Physics #Planet #Planetary habitability #Scientific Research and Discoveries #Solar System #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/588089
Accepted by ApJ. Several references added. 41 pages, 11 figures, 2 tables
arxiv created 2008/02/27 · openalex publication_date 2008/07/10 · arxiv updated 2009/12/01 · openalex created_date 2020/07/02 · openalex updated_date 2026/08/05
According to the standard liquid-water definition, the Earth is only partially habitable. We reconsider planetary habitability in the framework of energy balance models, the simplest seasonal models in physical climatology, to assess the spatial and temporal habitability of Earth-like planets. We quantify the degree of climatic habitability of our models with several metrics of fractional habitability. Previous evaluations of habitable zones may have omitted important climatic conditions by focusing on close solar system analogies. For example, we find that model pseudo-Earths with different rotation rates or different land-ocean fractions have fractional habitabilities that differ significantly from that of the Earth itself. Furthermore, the stability of a planet's climate against albedo-feedback snowball events strongly impacts its habitability. Therefore, issues of climate dynamics may be central in assessing the habitability of discovered terrestrial exoplanets, especially if astronomical forcing conditions are different from the moderate solar system cases.