Different climate states as a function of the intrinsic land and seafloor-weathering rates W_L0 and W_S0. The colors have the same meanings as in Figure 9. The four panels show differences in the insolation level S compared to that on modern Earth. Panels (a)–(d) use S = 1.1, 1, 0.9, and 0.8, respectively. In all cases, the outgassing rate is the same as that of modern Earth.