claim: after a natural orbitally driven warming, atmospheric carbon dioxide content increases 800 years later
evidence: The Devonian (/dɪˈvoʊn.i.ən, də-, dɛ-/ dih-VOH-nee-ən, də-, deh-) is a geologic period and system of the Paleozoic, spanning 60 million years from the end of the Silurian, 419.2 million years ago (Mya), to the beginning of the Carboniferous, 358.9 Mya.