Although high CO2 levels appear to be required to explain most times of ice-free climates in Earth history, previous calculations with a two-dimensional energy balance model (EBM) have suggested that the low thermal inertia associated with pole-centered supercontinents might allow seasonally snow-free conditions to develop in the absence of high CO2. This conclusion has been challenged by other EBM calculations with lower geographic resolution but more explicit model physics. To address this problem more directly we have undertaken a series of general circulation model (GCM) simulations with a new model (GENESIS) developed at the National Center for Atmospheric Research. For idealized pole-centered supercontinents we obtain mid summer south polar temperatures of 22 ¿C for the present orbital configuration and 15 ¿C with a modified orbital configuration favorable to cool summers. These results support the two-dimensional EBM calculations. However, their application to real-world situations of the Paleozoic is hampered by the fact that due to extremely high sea levels and decreased solar luminosity the best time periods for applying this concept (420-360 Ma) have supercontinent areas too small to yield an ice-free climate for all orbital configurations. Snow-free conditions with summer temperatures at the pole of 25 ¿C are simulated for a ''hot'' orbital configuration for one realistic geography configuration (Carboniferous, 300 Ma). These results indicate that while the basic idea of snow-free, pole-centered supercontinents is still theoretically possible, the real-world application to specific past time periods requires some modifications. Our reframed hypothesis states that for realistic geography and high CO2 levels, pole-edged supercontinents could have permanent snow cover, but pole-centered supercontinents would be snow-free in summer. ¿ American Geophysical Union 1993