next

Figure 1
Figure 1.

Stellar evolution and planetary temperature and atmospheric composition over the past 4.6 Ga, showing solar luminosity increase and predicted temperature of Earth with current atmosphere or no atmosphere (Ribas, 2009), envelope of permitted temperatures from gypsum and life (Walker, 1982), temperatures inferred from selected paleosols (Retallack, 2013, 2018; Retallack et al., 2016), and ice ages (Walker, 1982).

next