Stability diagrams of Earth-sized tidally locked planets with Earth-like (left panels) and pure CO₂ (right panels) atmospheres, and the associated minimum surface temperature. Quantities are plotted as functions of the stellar flux normalised by the Earth’s stellar flux, F_⋆/F_⊕ (horizontal axis), and the surface pressure, p_s, in logarithmic scale (vertical axis). From bottom to top: 0D (1 × 1 grid), 1D (1 × 50 grid), 1.5D (2 × 50 grid), and 2D (32 × 50 grid) instances of the meta-model. Large red dots indicate simulations where the atmosphere remained stable, while small blue dots indicate atmospheric collapse. The dashed orange (or dotted pink) line indicates the collapse pressure p_C;low (or p_C;up) corresponding to the lower (or upper) bound of the nightside surface temperature predicted by Wordsworth’s analytic model and given by Eq. (11).