Earth's Heat Flow in the Past

[Drakkith]

What effects would having 2-3 times the current heat flow of the Earth have had in the past? Would this have had a significant effect on global temperatures?

 

[Andre]

The average geothermal heat is 0.061 w/m2 which is some 4 orders of magnitude less than the energy balance of the earth surface. Hence no significant effect.

 

[billiards]

Convection in the mantle would have been more vigorous. This would have increased volcanism and seismicity at the surface.

 

[JesseC]

If it is true that there would have been more volcanism, would this not have had an indirect effect due to more frequent bursts of aerosols + volcanic gasses?

 

[Evo]

If it is true that there would have been more volcanism, would this not have had an indirect effect due to more frequent bursts of aerosols + volcanic gasses?

It has been known to cause cooling.

A volcanic winter is the reduction in temperature caused by volcanic ash and droplets of sulfuric acid obscuring the sun and raising Earth's albedo (increasing the Earth's reflectivity of solar radiation) after a large particularly explosive type of volcanic eruption. Long-term cooling effects are primarily dependent upon injection of sulfide compounds in aerosol forms into the upper atmosphere—the stratosphere—the highest, least active levels of the lower atmosphere where little precipitation occurs, requiring a lengthy time to wash the aerosols out of the region.

http://en.wikipedia.org/wiki/Volcanic_winter