Atmospheric chemical compositions of GJ 436b assuming different enrichment relative to the solar elemental abundances (Lodders 2010). Top panels: C/O ratio solar and metallicities of 10×   (left) and 100× (right) the solar value. Bottom panels: solar metallicity and C/O ratios of 0.5× (left) and 3× (right) the solar value. Results obtained with the full scheme of Venot et al. (2012; solid lines) and the reduced scheme (dotted lines) are superimposed and cannot be distinguished from one another.