claim: Scientists are "questioning the original idea that man-made global warming is what is causing the climate to change. "
evidence: The Silurian (/sɪˈljʊər.i.ən, saɪ-/ sih-LYOOR-ee-ən, sy-) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.8 million years ago (Mya), to the beginning of the Devonian Period, 419.2 Mya.