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This figure shows estimate of CO₂ concentrations (based on carbon-cycle and geochemical models, along with estimates based on proxy data) at the top

In the middle are two records of glaciation: the banded section shows intervals of glacial (dark blue) or cool climates (light blue; see text); also shown is latitudinal distribution of direct glacial evidence (tillites, striated bedrock, etc.) throughout the Phanerozoic.

At the bottom is two estimated of global temperature, based on data derived from fossilised sea shells. The blue line shows the temperature without correcting for CO₂ levels. The orange line shows the temperature after correction.

Figure based on Figures 2 and 4 in Royer et al, GSA Today: 2004; 14(3):4–10.