The end-Paleozoic great warming

According to the recent global mean surface temperature curve[1],the temperature continued to rise over a period of 45 million years at the end of the Paleozoic.The global mean temperature increased from 11.7 ℃ at 295 Ma at the beginning of the Permian to 32.7 ℃ at 250 Ma at the beginning of the Triassic,a warming of 21 ℃,one of the most dramatic warmings in the Phanerozoic(Fig.1a),which is referred to in this paper as the end-Paleozoic great warming(EPGW).Another significant warming event occurred in the mid-Cretaceous,when the global average temper-ature rose by 8.8 ℃ in 8 million years,reaching 28.2 ℃.The other two warming events of similar magnitude occurred after cooling events such as the Hirnantian Ice Age and the Cretaceous-Paleo-gene impact winter.Although the warming magnitudes were large,they mainly started from low points and did not exceed 25 ℃ after the warming events(Fig.1a).Other warming events with much smaller magnitudes include the early Cambrian,early Silurian,mid-late Silurian,Emsian,mid-Devonian,Frasnian,Devonian-Car-boniferous,early Pennsylvanian,Carnian,Norian,end-Triassic,Toarcian,Oxfordian,early Cretaceous,Albian,earliest Paleocene,Paleocene-Eocene,and Oligocene(Fig.1b).