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 Obliquity hypothesis can explain the Sturtian low-latitude glacial deposits when the supercontinent 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 conditions 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.