High obliquity as an alternative hypothesis to early and late proterozoic extreme climate conditions

Climate model simulations are used to assess the high obliquity hypothesis as a solution to Palaeoproterozoic and Neoproterozoic low-latitude glacial conditions. Climate model simulations show that if a low-latitude land mass is assembled it can explain the Paleoproterozoic glacial deposits. In the Neoproterozoic, the High Obliq-uity hypothesis can explain the Sturtian low-latitude glacial deposits when the super-continent Rodinia was located in low-latitudes. The High Obliquity hypothesis cannot explain Varangian high-latitude glacial deposits because of the high amounts of incident solar radiation, which will not allow for the accumulation of snow. However the high-latitude Varangian glacial deposits are the least reliable and should be viewed with caution. Moreover, if the majority of glacial deposits are in low-latitudes in support of the high obliquity hypothesis it is possible that local environmental con-ditions such as elevated topography may have been responsible for high latitude glacial deposits. The most problematic issue for high obliquity is the mechanism responsible for significantly reducing obliquity on a 100-million year time-scale.