The most recent global"icehouse hothouse"climate transition in earth history began during the Permian, Warmer polar conditions. relative to today, then persisted through the Mesozoic and into the Cenoxoic , We focus been on two Permian stages, the Sakmarian (285-280) and the Wordian (267-264) Ma; also known as the Kazanian), integrating floral with lithological data to determine their climates globally. These stage postdate the PermoCarboniferous glaciation bt retain a modertately steep equator-to-pole gradient, judging by the levelof floral and faunal diferentiation . Floral data provide a particlularly useful means of interpreting terrestrial paleoclimates, often revealing information abot climate gradations betwee"dry" and "wet" end-member lithological indicators such as evaporites and coals. We applied multivariate statistical analyses to the Permian floral data to calibrate the nature of floral and geographicla transitions as on aid to climate interpretation. We then classified Sakmarian and Wordiam terrestrial environments in a seies of regional biomes("climate zones") by inerating information on left morphologies and phytogeography with patterns of eolian sand, evaporite, and coal distributions, The data-derived biomes are compared here with modeled biomes resulting from new Sakmarian and Wordian climate model simulation for a range of CO_2 leels (one, four, adeight times the present levels) presented in our companion article. We provide a detailed grid cell comparison of the biome data and model results by geographic region, introducting a more rigorous approach to global paleoclimate studies.The simulations iwth four times the present CO_2 levels(4XCO_2) match the observations better than the simulitions with 1XCO_2 , and , at least in some areas, the simulations with 8XCO_2 match slighty better than those for 4XCO_2, Overall , the 4XCO_2 and 8XCO_2 biome simulations with 8XCO_2 biome simulations match the data reasonalbly well in the equatorial and midlatitudes as well as the northern high latitudes. However, even these highest CO_2 levels fail to product the temperate climates in high soughern latitutdes indicated by the data. The lack of sufficient ocean heat transport into polar latitutdes may be one of the factors responsibl for this cold bias of the climate model. Another factor could be the treatment of land surface processes and the lack of an interacive vegetation module. We discuss strengths and limitations of the data and model approaches and indicate future research directions
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