claim: at the end of recent ice ages, the concentration of carbon dioxide in the atmosphere started to rise only after temperatures began to climb.
evidence: Reconstructed temperature records for the last 420 million years indicate that atmospheric CO 2 concentrations peaked at ~2000 ppm during the Devonian ( ∼400 Myrs ago ) period, and again in the Triassic ( 220–200 Myrs ago ) period.