Calculated dayside composition in five gas giants and three plausible secondary atmospheres (hot volcano-like, hot reducing N₂/CH₄, and warm oxidizing N₂/O₂ atmosphere). Dotted lines correspond to the initial composition (chemical equilibrium for the gas giants and equal uniform abundances for secondary atmospheres), dashed lines to a calculation where the initial temperature does not further evolve (only for the gas giants), and solid lines to a self-consistent calculation where temperature and chemical composition evolve together.