Impacts of Atmospheric Carbon Species and Stellar Type on Climates of Terrestrial Planets

Abstract

The climates of terrestrial planets are largely determined by the composition of their atmospheres and spectral types of their host stars. Previous studies suggest a wide range of carbon species abundances (CO\textsubscript{2}, CO, and CH\textsubscript{4}) can result from variations in reducing fluxes and stellar spectral types which influence photochemistry. However, a systematic investigation of how varying carbon species, particularly CO, affect planetary climates across wide parameter spaces remains limited. Here, we employ a one-dimensional radiative-convective equilibrium model to examine the dependence of planetary climate on the abundances of carbon species and host star type. We find that CO, due to weak absorption of stellar radiation, induces only moderate changes in stratospheric temperature, while its effect on surface temperature is negligible. Under Earth-like $p_{{\mathrm{N}}_2}$ (where $p_{\mathrm{i}}$ is the partial pressure on the surface of species i), for cases with fixed $p_{\mathrm{C}{\mathrm{O}}_2}$, increase in CO leads to surface cooling on planets orbiting Sun-like stars unless the sum of $p_{\mathrm{C}{\mathrm{O}}_2}$ and $p_{\mathrm{C}{\mathrm{H}}_4}$ exceeds $\sim$1 bar. Whereas it results in surface warming for planets around M-type stars. When the total pressure of carbon species is fixed, converting CO\textsubscript{2} or CH\textsubscript{4} into CO always induces cooling. These effects arise from a combination of CO Rayleigh scattering, pressure broadening of greenhouse gas absorption lines, and \textcolor{red}{varying water vapor levels}. We further discuss how CO- and CH\textsubscript{4}-driven cooling (warming) can trigger positive (negative) climate-photochemistry feedback, influencing atmospheric evolution. Additionally, we suggest CO-rich planets may be less susceptible to water loss and atmospheric oxidation due to lower stratospheric water vapor content.

References in corpus (33)

• Habitable Zones Around Main-Sequence Stars: New Estimates
• The Climate of Early Mars
• Constraining the climate and ocean pH of the early Earth with a geological carbon cycle model
• 3D modelling of the early Martian Climate under a denser CO2 atmosphere: Temperatures and CO2 ice clouds
• The Pale Orange Dot: The Spectrum and Habitability of Hazy Archean Earth
• Was Venus the First Habitable World of our Solar System?
• Thermal emission from the Earth-sized exoplanet TRAPPIST-1 b using JWST
• Atmospheric reconnaissance of the habitable-zone Earth-sized planets orbiting TRAPPIST-1
• No thick carbon dioxide atmosphere on the rocky exoplanet TRAPPIST-1 c
• Assessing the Habitability of the TRAPPIST-1 System Using a 3D Climate Model
• Modelling climate diversity, tidal dynamics and the fate of volatiles on TRAPPIST-1 planets
• Abiotic O${}_2$ Levels on Planets around F, G, K, and M Stars: Possible False Positives for Life?
• Water loss from terrestrial planets with CO2-rich atmospheres
• High Stellar FUV/NUV Ratio and Oxygen Contents in the Atmospheres of Potentially Habitable Planets
• Strange messenger: A new history of hydrogen on Earth, as told by Xenon
• Venusian Habitable Climate Scenarios: Modeling Venus through time and applications to slowly rotating Venus-Like Exoplanets
• The MUSCLES Treasury Survey. V. FUV Flares on Active and Inactive M Dwarfs
• The Role of Plate Tectonic-Climate Coupling and Exposed Land Area in the Development of Habitable Climates on Rocky Planets
• Day-night cloud asymmetry prevents early oceans on Venus but not on Earth
• Pale Orange Dots: The Impact of Organic Haze on the Habitability and Detectability of Earthlike Exoplanets
• Resolving Orbital and Climate Keys of Earth and Extraterrestrial Environments with Dynamics 1.0: A General Circulation Model for Simulating the Climates of Rocky Planets
• Carbon cycling and habitability of Earth-size stagnant lid planets
• Atmospheres of Rocky Exoplanets
• A Lower Limit of Atmospheric Pressure on Early Mars Inferred from Nitrogen and Argon Isotopic Compositions
• Methane bursts as a trigger for intermittent lake-forming climates on post-Noachian Mars
• A Methane Extension to the Classical Habitable Zone
• Carbonate-Silicate Cycle Predictions of Earth-like Planetary Climates and Testing the Habitable Zone Concept
• Dry Late Accretion inferred from Venus' coupled atmosphere and internal evolution
• O2- and CO-Rich Atmospheres for Potentially Habitable Environments on TRAPPIST-1 Planets
• Ozone chemistry on tidally locked M dwarf planets
• A nitrogen-rich atmosphere on ancient Mars consistent with isotopic evolution models
• Lightning-induced chemistry on tidally-locked Earth-like exoplanets
• Relative abundances of CO2, CO, and CH4 in atmospheres of Earth-like lifeless planets