Editing Supercontinent (section)

===Temperature===

Even though during the Archaean solar radiation was reduced by 30 percent and the [[Cambrian]]-[[Precambrian]] boundary by 6 percent, the Earth has only experienced three [[Ice age|ice ages]] throughout the Precambrian.<ref name=flutaeu /> Erroneous conclusions are more likely to be made when models are limited to one climatic configuration (which is usually present-day).<ref name="baum">Baum, Steven K., and Thomas J. Crowely. "Milankovitch Fluctuations on Supercontinents." Geophysical Research Letters. 19 (1992): 793–796. Print.</ref>

Cold winters in continental interiors are due to rate ratios of radiative cooling (greater) and heat transport from continental rims. To raise winter temperatures within continental interiors, the rate of heat transport must increase to become greater than the rate of radiative cooling. Through climate models, alterations in atmospheric CO<sub>2</sub> content and ocean heat transport are not comparatively effective.<ref name=baum />

CO<sub>2</sub> models suggest that values were low in the late Cenozoic and Carboniferous-Permian glaciations. Although early Paleozoic values are much larger (more than 10 percent higher than that of today). This may be due to high seafloor spreading rates after the breakup of Precambrian supercontinents and the lack of land plants as a [[carbon sink]].<ref name=crowley />

During the late Permian, it is expected that seasonal Pangaean temperatures varied drastically. Subtropic summer temperatures were warmer than that of today by as much as 6–10 degrees, and mid-latitudes in the winter were less than −30 degrees Celsius. These seasonal changes within the supercontinent were influenced by the large size of Pangaea. And, just like today, coastal regions experienced much less variation.<ref name=flutaeu />

During the Jurassic, summer temperatures did not rise above zero degrees Celsius along the northern rim of Laurasia, which was the northernmost part of Pangaea (the southernmost portion of Pangaea was Gondwana). Ice-rafted [[dropstone]]s sourced from Russia are indicators of this northern boundary. The Jurassic is thought to have been approximately 10 degrees Celsius warmer along 90 degrees East [[paleomagnetism|paleolongitude]] compared to the present temperature of today's central Eurasia.<ref name=baum />