Climatic implications of the variable obliquity explanation of Cretaceous-Paleogene high-latitude floras

The record of high-latitude Cretaceous-Paleogene floras has been interpreted as indicative of warmth and climatic equability and has also been the basis for arguments of reduced obliquity. Climate model simulations suggest that a reduced obliquity will result in a substantial polar cooling that is incompatible with the interpretation for polar warmth. Paleobiologic adaptations to low light levels may be an alternative to a variable obliquity.