Analogous response of temperate terrestrial exoplanets and Earth's climate dynamics to greenhouse gas supplement

TL;DR

This study compares the effects of greenhouse gas increases on Earth's and an exoplanet's atmospheres, revealing similar climate responses despite their different climate states, using advanced climate models.

Contribution

It demonstrates an analogous atmospheric response to CO2 supplementation in both Earth and TRAPPIST-1e, providing new insights into exoplanet habitability and climate dynamics.

Findings

CO2 supplement causes amplified warming in non-irradiated regions

Adding CO2 increases surface stability but decreases atmospheric stability at low pressures

Earth and TRAPPIST-1e share similar climate dynamic responses to greenhouse gases

Abstract

Humanity is close to characterizing the atmospheres of rocky exoplanets due to the advent of JWST. These astronomical observations motivate us to understand exoplanetary atmospheres to constrain habitability. We study the influence greenhouse gas supplement has on the atmosphere of TRAPPIST-1e, an Earth-like exoplanet, and Earth itself by analyzing ExoCAM and CMIP6 model simulations. We find an analogous relationship between CO2 supplement and amplified warming at non-irradiated regions (night side and polar) - such spatial heterogeneity results in significant global circulation changes. A dynamical systems framework provides additional insight into the vertical dynamics of the atmospheres. Indeed, we demonstrate that adding CO2 increases temporal stability near the surface and decreases stability at low pressures. Although Earth and TRAPPIST-1e take entirely different climate states, they share the relative response between climate dynamics and greenhouse gas supplements.