GLOBAL TEMPERATURESTHROUGHTIME The Earth's temperature has Present temperature changed dramatically over geologic time. Colder Warmer Quaternory START OF 下HeMIS件4E我E 1.75 Plocene 25 There were palm trees in Alaska 5 LARGE ICE SHET5 N ANTA典CTCA during the Cretaceous! Miocene 15 23.8 F ST ICE SHEET Oligocene 33.7 Eocene 54.8 Paleocene 65 Cretoceous 140 Jurassic 205 Triassic 245 Permian PERMO- 地球科学告诉我们： 290 CA气BONIFE我OU5 GLACIATION Carboniferous 354 以今鉴古、借古通今 Devonian 417 Silurian 443Shanghai Jiao Tong University The Earth’s temperature has changed dramatically over geologic time. There were palm trees in Alaska during the Cretaceous! 地球科学告诉我们： 以今鉴古、借古通今