Panel (a): an overview of the T-dependence of methane absorption cross sections (cm²/molecule) in the triacontad range at four temperatures 295, 400, 600, and 1000 K: low-resolution (R = 2 cm⁻¹) simulations of observations (up) and theory (down). Panel (b): log-scale comparison of observed (up) and theoretical (down) methane absorption X-sections at the triacontad range for two temperatures T = 600 K (green) and 1000 K (red): medium-resolution (R = 0.2 cm⁻¹) simulations.